Synthesis, Characterization, and Catalytic Behaviors in Isoprene Polymerization of Pyridine-Oxazoline-Ligated Cobalt Complexes

A family of pyridine-oxazoline-ligated cobalt complexes L2CoCl23a-h were synthesized and characterized. Determined via single-crystal X-ray diffraction, complexes 3a and 3d, ligated by two ligands, displayed a distorted tetrahedral coordination of a cobalt center. The X-ray structure indicated the pyridine-oxazoline ligands acted as unusual mono-dentate ligands by coordinating only to Noxazoline. Upon activation with AlEt2Cl (diethylaluminum chloride), these cobalt complexes all exhibited high catalytic activity (up to 2.5 × 106 g·molCo-1·h-1), affording cis-1,4-co-3,4-polyisoprene with molecular weights of 4.4-176 kg mol-1 and a narrow Ð of 1.79-3.42, suggesting a single-site nature of the active sites. The structure of cobalt catalysts and reaction parameters, especially co-catalysts and the reaction temperature, all have significant influence on the polymerization activity but not on the microstructure of polyisoprene.

Long scleral tunnel technique for prevention of drainage tube-related complications during Ahmed glaucoma valve implantation

To evaluate the safety and efficacy of modified Ahmed glaucoma valve (AGV) implantation (long scleral tunnel technique) in the treatment of neovascularization glaucoma (NVG). This retrospective observational case series included 23 patients (23 eyes) diagnosed with NVG secondary to proliferative diabetic retinopathy from January 2020 to June 2021. All 23 cases received anti-vascular endothelial growth factor treatment. Then, after 3 to 7 days, these cases were treated with modified AGV implantation (long scleral tunnel technique) and were followed up for at least 6 months. The best corrected visual acuity, intraocular pressure, numbers of antiglaucoma medications used, and postoperative complications were observed at 1 week and 1, 3, and 6 months after treatment. With treatment, the mean best corrected visual acuity improved significantly (P < .001) from 1.62 ± 0.52 logMAR preoperatively to 1.29 ± 0.36 logMAR at the 6-month follow-up. The mean postoperative intraocular pressure was significantly lower than that before modified AGV implantation during follow-up period, decreasing from 45.48 ± 7.86 mm Hg preoperatively to 14.87 ± 1.96 mm Hg at 1 week, 18.39 ± 2.25 mm Hg at 1 month, 16.61 ± 1.47 mm Hg at 3 months, and 17.48 ± 1.38 mm Hg at 6 months (F = 256.646, P < .001). The median number of antiglaucoma medications used by patients also significantly decreased from 3 (3-4) preoperatively to 0 (0-1) at the 6-month follow-up after surgery (Z = -4.248, P < .001). Postoperative complications included hyphema in 2 cases and vitreous hemorrhage in 1 case, and all 3 patients achieved satisfactory recovery with treatment. No drainage tube-related complications occurred among our patients. Long scleral tunnel technique is a safe and effective surgical treatment for NVG with fewer drainage tube-related complications.

[Gut microbiota and immune-related diseases]

There are direct and indirect interactions between gut microbiota and host immune response, which can have a multifaceted impact on host health. Dysbiosis caused by disturbances in the gut microbiota is associated with susceptibility to many diseases, especially immune-related diseases. Based on the research results in recent years, this paper introduced the mechanism of the interaction between gut microbiota and host immunity, and expounded the role of gut microbiota in the occurrence and development of immune-related diseases, including intestinal system diseases such as inflammatory bowel disease and other systemic diseases such as rheumatoid arthritis, and summarized disease treatment strategies targeting gut microbiota. A better understanding of the research progress of gut microbiota and immune-related diseases will help us in the prevention and management of such diseases, and broaden our path to discover disease intervention targets.

Copper-catalyzed regioselective C2-H chlorination of indoles with para-toluenesulfonyl chloride

A copper-catalyzed, pyrimidine directed regioselective C-H chlorination of indoles with para-toluenesulfonyl chloride (TsCl) has been developed. The reactions proceeded smoothly in the presence of 20 mol% of Cu(OAc)₂ as the catalyst and TsCl as the chlorine source, delivering C2-chlorinated indoles with structural diversity in moderate to excellent yields. Mechanistic studies suggested that single electron transfer (SET) from Cu(II) to TsCl accompanied by the release of the p-toluenesulfonyl radical and the related Cu(III)Cl species might be involved in the reactions.

The Novel Function of Unsymmetrical Chiral CCN Pincer Nickel Complexes as Chemotherapeutic Agents Targeting Prostate Cancer Cells

We report that the pincer nickel complexes display prostate cancer antitumor properties through inhibition of cell proliferation. Notably, they display better antitumor properties than cisplatin. Mechanistic studies reveal that these pincer nickel complexes trigger cell apoptosis, most likely due to cell cycle arrest. Interestingly, these complexes also inhibit androgen receptor (AR) and prostate-specific antigen (PSA) signaling, which are critical for prostate cancer survival and progression. Our study reveals a novel function of pincer nickel complexes as potential therapeutic drugs in prostate cancer.

Chiral (phosphine)-(imidazoline) PCN pincer palladium(II) complexes: synthesis and application in asymmetric hydrophosphination of 2-alkenoylpyridines with diphenylphosphine

A series of new chiral PCN pincer Pd(II) complexes 3a−l with aryl-based (phosphine)-(imidazoline) ligands were conveniently synthesized from readily available starting materials with the key step being phosphination/C−H palladation reaction....

Microwave-Assisted Ruthenium- and Rhodium-Catalyzed Couplings of α-Amino Acid Ester-Derived Phosphinamides with Alkynes

Two different types of new phosphinamide α-amino ester derivatives have been prepared in moderate to high yields via ruthenium(II) and rhodium(III)-catalyzed ortho-C-H functionalization under microwave irradiation. Specifically, the ortho-alkenylated phosphinamides were produced through coupling of phosphinamides containing an α-substituted or α,α-disubstituted α-amino ester with internal alkynes under ruthenium catalysis. In contrast, Ru and the more effective Rh-catalyzed coupling of the α-unsubstituted glycine ester phosphinamide with alkynes resulted in formation of oxidative annulation products, phosphaisoquinolin-1-ones. The developed methods feature the use of easily accessible starting materials, short reaction time, exclusive E-stereoselectivity (for ortho-alkenylation) and good functional group tolerance. The alkenylation reaction was readily scaled up to gram scale. Furthermore, the obtained alkenylated phosphinamide could be transformed into P-containing dipeptides through hydrolysis of the ester group in the catalysis product and subsequent condensation with an α-amino ester.

Correction: Diastereoselective synthesis of chiral 3-substituted isoindolinones via rhodium(III)-catalyzed oxidative C-H olefination/annulation

Correction for 'Diastereoselective synthesis of chiral 3-substituted isoindolinones via rhodium(iii)-catalyzed oxidative C-H olefination/annulation' by Xue-Hong Li et al., Org. Biomol. Chem., 2021, DOI: 10.1039/d1ob00656h.

Diastereoselective synthesis of chiral 3-substituted isoindolinones via rhodium(III)-catalyzed oxidative C-H olefination/annulation

A new method for the direct and stereoselective synthesis of 3-substituted isoindolinones via Rh(iii)-catalyzed chiral N-sulfinyl amide directed asymmetric [4 + 1] annulation of benzamides with acrylic esters has been developed. The reaction proceeded through an oxidative C-H olefination and a subsequent cyclization by intramolecular aza-Michael addition, producing a series of diastereoisomeric chiral isoindolinones (20 examples) in generally good yields with a dr value up to 5.5 : 1. The absolute configurations of the newly formed C-stereocenters in the major and minor diastereomers of the catalysis product have been determined by X-ray crystal diffraction analysis to be S and R, respectively. The separation of the major diastereoisomers from the catalysis products and subsequent removal of the N-sulfinyl chiral auxiliary afforded enantiomerically pure (S)-isoindolinones. The application of the obtained (S)-isoindolinones in the synthesis of several biologically active isoindolinones such as (S)-PD172938, (S)-pazinaclone and (S)-pagoclone is presented.

Inadvertent globe penetration during retrobulbar anesthesia: A case report

BACKGROUND

To report the possible reasons for needle perforation and complications related to perforation, as well as the clinical management of subretinal hemorrhage (SRH) during retrobulbar injection.

CASE SUMMARY

A 65-year-old female was scheduled to undergo pars plana vitrectomy (PPV) in her left eye for rhegmatogenous retinal detachment (RRD). During retrobulbar anesthesia, needle perforation of the globe occurred. Massive SRH in the inferotemporal quadrant together with vitreous hemorrhage were observed. The patient underwent PPV combined with retinotomy for removal of the massive SRH. After earlier surgical intervention, successful reattachment of the retina was achieved.

CONCLUSION

Inadvertent globe penetration during retrobulbar anesthesia is associated with a poor prognosis and may result in blindness. Timely detection and earlier intervention may be beneficial.

[Characteristics and predictors of postoperative outcome of Crohn disease patients requiring abdominal surgery: a series of 1 048 cases from a single inflammatory bowel disease centre]

Objective: To examine the clinical characteristics, the potential relative factors for postoperative abdominal septic complications, and prognosis factors of surgical recurrence of Crohn disease (CD) patients after the first surgery. Methods: All the CD patients from Department of General Surgery, Jinling Hospital, Medical School of Nanjing University who had undergone at least one abdominal surgery from January 2007 to December 2017 were included for retrospective analysis. Hospital records were reviewed for information on clinical characteristics. Relative factors of postoperative abdominal septic complications were accessed by Logistic regression models, and prognosis factors of surgical recurrence were accessed by Cox proportional hazards regression models. Results: There were 1 048 patients included (733 males and 315 females), accounting for 1 513 operations. The age was 31(17) years and the length of resected small bowel was 30.0(40.0) cm at the first resection, 20.0(35.0) cm at the second resection, and 20.0(23.5) cm at the third resection. The length of resected small bowel was 25.0(40.0) cm at any resection. At the first abdominal surgery, 70.99%(744/1 048) patients were aged between 17 and 40 years, 66.98%(702/1 048) patients had ileocolonic disease, and 60.40%(633/1 048) patients had penetrating behavior. Penetrating behavior (OR=8.594, 95%CI: 3.397 to 21.740, P<0.01) and current smoking status (OR=2.671, 95%CI: 1.044 to 6.832, P=0.040) were significantly associated with an increased risk of postoperative septic complications, whereas staged operation (OR=0.360, 95%CI: 0.184 to 0.707, P=0.003) was associated with a decreased risk. Male gender (HR=1.500, 95%CI: 1.128 to 1.995, P=0.005), upper gastrointestinal disease (HR=1.526, 95%CI: 1.033 to 2.255, P=0.034), penetrating behavior (HR=1.506, 95%CI: 1.132 to 2.003, P=0.005) and emergency surgery (HR=1.812, 95%CI: 1.375 to 2.387, P<0.01) were significantly associated with an increased risk of postoperative surgical recurrence, whereas staged operation (HR=0.361, 95%CI: 0.227 to 0.574, P<0.01) was significantly associated with a decreased risk. Conclusions: In this cohort of CD patients receiving abdominal surgery from an inflammatory bowel disease center, the median age was 31 years and the median length of resected small bowel was 30 cm, at first resection. Patients who have risk factors of adverse postoperative outcome may be benefited from staged surgical approach.

Synthesis of Chiral Bis(3-indolyl)methanes Bearing a Trifluoromethylated All-Carbon Quaternary Stereocenter via Nickel-Catalyzed Asymmetric Friedel-Crafts Alkylation Reaction

Bis(3-indolyl)methanes are well-known natural products with a broad range of important biological functions including cancer cell growth inhibition and antimicrobial activity. Incorporation of a trifluoromethyl group is known to have a profound effect on the parent compound's biological activities. Here, an efficient method for the synthesis of chiral trifluoromethylated bis(3-indolyl)methanes via a catalytic asymmetric Friedel-Crafts (F-C) alkylation reaction has been established. Both enantiomers of the catalysis products can be obtained by tuning the chiral substituents of the catalyst. With 5 mol % of the Ni(II)/(imidazoline-oxazoline) complex as the catalyst, the F-C reaction of indoles with β-CF₃-β-(3-indolyl)nitroalkenes proceeded well to afford a series of chiral bis(3-indolyl)methanes bearing a trifluoromethylated all-carbon quaternary stereocenter in generally good yields with excellent enantioselectivities (up to 98% yield and 94% ee). Furthermore, by interchanging the indole moieties of the two reactants, indole vs β-CF₃-β-(3-indolyl)nitroalkene in the F-C reaction, both enantiomers of a given trifluoromethylated bis(3-indolyl)methane were obtained with high enantioselectivities (89-94% ee) upon removal of the indole N-protecting group in the F-C products. The current work represents the first general catalytic enantioselective approach to the important class of trifluoromethylated bis(3-indolyl)methanes.

Palladium-catalyzed δ-selective reductive Heck reaction of alkenyl carbonyl compounds with aryl iodides and bromides

A simple, operationally convenient and highly regioselective palladium-catalyzed reductive Heck reaction of alkenyl carbonyl compounds with aryl iodides and bromides has been developed to afford structurally diverse δ-aryl pentanoic acid derivatives.

Chiral palladium pincer complexes for asymmetric catalytic reactions

Palladium pincer complexes, containing a monoanionic terdentate ligand composed of an anionic aryl carbon atom and two mutually compatible donor sites, have aroused considerable interest since their first reports in the late 1970s. The high stability of the Pd pincer complexes and particularly their high modularity make these species ideal candidates for catalysis. Furthermore, the nature of the meridional coordination of the pincer ligands, and along with this their ability to enforce a stereo-specific environment around the Pd center, provide a good opportunity for developing chiral Pd pincer catalysts. Thus, a broad variety of chiral Pd pincer complexes have been prepared by the introduction of various stereochemical centers in the pincer skeletons. These chiral Pd pincer complexes have been successfully applied to many asymmetric catalytic reactions such as hydrophosphination reactions, allylation of aldehydes and imines, Michael and aldol reactions, Suzuki-Miyaura reactions as well as reactions of nitrile compounds with imines. This review focuses on the synthetic methods and the applications of chiral Pd pincer complexes in asymmetric catalysis.

Nickel(ii)-catalyzed C(sp2)-H sulfuration/annulation with elemental sulfur: selective access to benzoisothiazolones

The first nickel(ii)-catalyzed direct sulfuration/annulation of C(sp²)-H bonds with elemental sulfur has been achieved by using 2-amino alkylbenzimidazole (MBIP-amine) as a N,N-bidentate directing group. This strategy tolerates a wide range of functional groups, furnishing structurally diverse benzoisothiazolone derivatives with benzimidazole skeletons in moderate to excellent yields in a simple and efficient way.

Cobalt(ii)/(imidazoline–oxazoline)-catalyzed enantioselective Michael addition of 2-acetyl azaarenes to β-CF3-β-disubstituted nitroalkenes

Cobalt(ii)/(imidazoline–oxazoline)-catalyzed enantioselective Michael addition of 2-acetyl azaarenes to β-CF₃-β-disubstituted nitroalkenes is reported, providing chiral compounds with an all-carbon quaternary stereocenter in high yields and excellent enantioselectivities.

[The value of postoperative C-reactive protein in predictive diagnosis of postoperative intra-abdominal septic complications for patients with Crohn disease]

OBJECTIVE

To analyze the value of postoperative C-reactive protein (CRP) in predictive diagnosis of postoperative intra-abdominal septic complications (IASC) for patients with Crohn disease (CD).

METHODS

Clinical data of patients with CD received intestinal resection and anastomosis surgery at Research Institute of General Surgery, Jinling Hospital from January 2011 to January 2015 were analyzed. Patients were divided into two groups by whether suffer from IASC 1 month after surgery, including IASC group and no-IASC group. Propensity score matching method was used to match the general clinical data. A total of 54 patients were analyzed, including IASC 17 cases, no-IASC 37 cases. Postoperative CRP at 1-day and 3-day were compared between the two groups using t test. Receiver operator characteristic (ROC) cure was used to analyze the value of postoperative CRP in predictive diagnosis of IASC.

RESULTS

IASC group had higher levels of CRP at 1-day ((78±13) mg/L vs. (54±19) mg/L, t=4.633, P=0.000) and 3-day ((103±19) mg/L vs. (69±21) mg/L, t=5.859, P=0.000) after surgery than no-IASC group. ROC analysis showed that the CRP 3-day after surgery cut-off point value of 81.45 mg/L, as used for the predictive diagnosis of IASC, provided a sensitivity of 94.1%, a specificity of 82.9%, an area under the curve of 0.90, better than CRP 1-day after surgery.

CONCLUSION

Postoperative CRP can be used as a predictive diagnosis of IASC for CD patients received intestinal resection and anastomosis surgery.

PCN pincer palladium(II) complex catalyzed enantioselective hydrophosphination of enones: synthesis of pyridine-functionalized chiral phosphine oxides as NC(sp(3))O pincer preligands

A series of chiral PCN pincer Pd(II) complexes VI-XIII with aryl-based aminophosphine-imidazoline or phosphinite-imidazoline ligands were synthesized and characterized. They were examined as enantioselective catalysts for the hydrophosphination of enones. Among them, complex IX, which features a Ph2PO donor as well as an imidazoline donor with (4S)-phenyl and N-Tol-p groups, was found to be the optimal catalyst. Thus, in the presence of 2-5 mol % of complex IX a wide variety of enones reacted smoothly with diarylphosphines to give the corresponding chiral phosphine derivatives in high yields with enantioselectivities of up to 98% ee. In particular, heteroaryl species such as 2-thienyl-, 2-furyl-, and 2-pyridinyl-containing enones that have a strong coordination ability to the Pd center were also appropriate substrates for the current catalytic system. For example, hydrophosphination of 2-alkenoylpyridines with diphenylphosphine followed by oxidation with H2O2 afforded the corresponding pyridine-functionalized chiral phosphine oxides in good yields with good to excellent enantioselectivities (10 examples, up to 95% ee). Furthermore, it had been demonstrated that the obtained pyridine-containing phosphine oxide acted as a tridentate ligand in the reaction with PdCl2 to form an intriguing NCsp(3)O pincer Pd(II) complex via Csp(3)-H bond activation, which to our knowledge is the first example of a chiral DCsp(3)D' Pd pincer (D ≠ D'; D and D' denote donor atoms such as P, N, etc.).

Efficient and scalable Pd-catalyzed double aminocarbonylations under atmospheric pressure at low catalyst loadings

A scalable approach to access various pharmaceutical and structurally intriguing N-substituted phthalimides via double aminocarbonylations has been established under atmospheric CO pressure with a robust Pd-NHC complex at a low catalyst loading.

Feasibility and efficacy of combined cisplatin plus irinotecan chemotherapy for gastroenteropancreatic neuroendocrine carcinomas

No standard treatment is currently available for gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC). Therefore, we conducted this study to evaluate the effect of the combination of irinotecan and cisplatin in the treatment of GEP-NECs. Clinical data of 16 locally advanced or metastatic GEP-NEC patients treated with irinotecan plus cisplatin regimen in our center from September 2009 to August 2011 were reviewed. The regimen included 2-week cycles of 180 mg/m(2) irinotecan and 50 mg/m(2) cisplatin on day 1. Median age was 57 years. The overall response rate was 57.1%, with a disease control rate of 78.6%. One patient achieved pathologic complete response and underwent esophagectomy after chemotherapy. Two patients who had gotten progressive disease were given sequential octreotide long-acting release (LAR) treatment and got disease progression again within 1 month. Six patients who achieved disease control received octreotide LAR as maintenance treatment. The total number of cycles of octreotide was 41, with a median of 4.5 (3-20 cycles). The progression-free survival was 5.5 months, with overall survival of 10.6 months. Grades 3-4 hematological adverse events (AEs) occurred in 10 patients (62.5%) and 3 patients (18.7%) suffered grades 3-4 non-hematological AEs; no patient died of AEs. The irinotecan plus cisplatin chemotherapy is moderately effective and tolerable well tolerated in advanced or metastatic GEP-NEC patients; octreotide LAR may be a good maintenance treatment and should be considered as a treatment option for these patients in the future.

Manipulation of monoubiquitin improves salt tolerance in transgenic tobacco

Ubiquitin (Ub) is regarded as a stress protein involved in many stress responses. In this paper, sense and antisense transgenic tobacco plants, as well as the wild type and vector control, were used to study the role of Ub in salt tolerance of plants. In sense Ta-Ub2 transgenic tobacco plants, there was higher expression of Ub protein conjugates than in the wild type and vector control, but the reverse trend was observed in antisense Nt-Ub1 transgenic plants. The germination rate of tobacco seed, growth status and photosynthesis of the tobacco plants suggested that over-expressing Ub promoted the growth of transgenic tobacco plants and enhanced their salt tolerance, but the opposite effect was seen in plants with repressed Ub expression. Changes in antioxidant capacity may be one of the mechanisms underlying Ub-regulated salt tolerance. Furthermore, improved tolerance to a combination of stresses was also observed in the sense transgenic tobacco plants. These findings imply that Ub is involved in the tolerance of plants to abiotic stress.

Symmetrical and unsymmetrical pincer complexes with group 10 metals: synthesis via aryl C-H activation and some catalytic applications

Aryl-based pincer metal complexes with anionic terdentate ligands have been widely applied in organic synthesis, organometallic catalysis and other related areas. Synthetically, the most simple and convenient method for the construction of these complexes is the direct metal-induced C(aryl)-H bond activation, which can be fulfilled by choosing the appropriate functional donor groups in the two side arms of the aryl-based pincer preligands. In this perspective, we wish to summarize some results achieved by our group in this context. Successful examples include symmetrical chiral bis(imidazoline) NCN pincer complexes with Ni(II), Pd(II) and Pt(II), bis(phosphinite) and bis(phosphoramidite) PCP pincer Pd(II) complexes, unsymmetrical (pyrazolyl)phosphinite, (amino)phosphinite and (imino)phosphinite PCN pincer Pd(II) complexes, chiral (imidazolinyl)phosphinite and (imidazolinyl)phosphoramidite PCN pincer complexes with Ni(II) and Pd(II) as well as unsymmetrical (oxazolinyl)amine and (oxazolinyl)pyrazole NCN' pincer Pd(II) complexes. Among them, the P-donor containing complexes are efficiently synthesized by the "one-pot phosphorylation/metalation" method. The obtained symmetrical and unsymmetrical pincer complexes have been used as catalysts in Suzuki-Miyaura reaction (Pd), asymmetric Friedel-Crafts alkylation of indole with trans-β-nitrostyrene (Pt) as well as in asymmetric allylation of aldehyde and sulfonimine (Pd). In the Suzuki couplings conducted at 40-50 °C, some unsymmetrical Pd complexes exhibit much higher activity than the related symmetrical ones which can be attributed to their faster release of active Pd(0) species resulting from the hemilabile coordination of the ligands. Literature results on the synthesis of some related pincer complexes as well as their activities in the above catalytic reactions are also presented.

Post-operative imatinib in patients with intermediate or high risk gastrointestinal stromal tumor

AIMS

This study aims to determine whether adjuvant treatment with imatinib improves recurrence-free survival (RFS) in Chinese patients undergoing complete resection of localized primary gastrointestinal stromal tumor (GIST) compared with those not receiving adjuvant therapy. We also sought a correlation between c-KIT mutations and RFS.

METHODS

Patients who had undergone complete tumor resection with intermediate or high risk of recurrence were enrolled in a single-center, non-randomized, prospective study. Patients either received adjuvant imatinib therapy (400 mg once-daily) for 3 years or did not. Mutation analyses of c-KIT were performed on available archival tumor samples.

RESULTS

105 patients were enrolled: 56 in the treatment group and 49 in the control group. Median follow-up was 45(43.1-46.9) months. RFS at 1, 2 and 3 years were higher in the treatment group than in the control group (100% vs. 90% at 1 year; 96% vs. 57% at 2 years; 89% versus 48% at 3 years, P < 0.001, HR = 0.188). Subgroup analyses showed that adjuvant therapy significantly decreased the risk of recurrence in patients whether at high risk or at intermediate risk compared with control patients (3-year RFS: 95% vs. 72%, in intermediate risk; 85% versus 31% in high risk; P < 0.001). In addition, imatinib adjuvant treatment decreased the risk of death (P = 0.025, [corrected] HR = 0.254).

CONCLUSIONS

Adjuvant imatinib can improve 1-, 2- and 3-year RFS rates in patients at intermediate or high risk of recurrence after complete tumor resection.

CLINICAL TRIALS REGISTRATION NUMBER

ChiCTR-TCC-00000582.

Room Temperature Suzuki Reactions in Aqueous Media under Air by Palladium(II) Complexes with Pyrazole Derived Ligands

Two new palladium complexes with pyrazole derived ligands 2a–2b have been easily prepared and well characterized by elemental analysis, 1H NMR, 13C NMR, and IR spectra. Their detailed structures are determined by a single-crystal X-ray analysis of 2a. The two compounds were successfully applied to the Suzuki coupling reactions of aryl bromides with phenylboronic acid, in aqueous solution at room temperature under air, giving the desired coupled products in good to excellent yields with catalyst loadings as low as 0.01–0.05 mol-%.