Stereoselective Synthesis of Ribofuranoid exo-Glycals by One-Pot Julia Olefination Using Ribofuranosyl Sulfones

Nontraditional Synthesis of Disaccharides via Acyclic Vinylic Ether Intermediates: Catalytic C-O Cross-Coupling as the Enabling Link

We describe complementary methods for synthesizing acyclic vinylic ethers from two carbohydrate-derived synthons. We compare a nonstereoselective olefination approach with a stereoselective catalytic C-O cross-coupling method, preparing 1,2-disubstituted vinylic ethers with complexity on both sides of the ether linkage. Upon epoxidation/in situ oxacyclization of acyclic vinylic ethers, we synthesized disaccharides with α-d-galacto-, α-d-talo-, β-d-allo-, and α-d-altropyranoside stereochemistry, from d-lyxose and d-ribose precursors. Stereoselective CuI/CyDMEDA-catalyzed C-O cross-couplings offer considerable potential for broadly implementing this nontraditional strategy for glycoside synthesis.

Asymmetric sulfonylation with sulfur dioxide surrogates: a new access to enantiomerically enriched sulfones

Enantiomerically enriched sulfones occupy a prominent position in pharmaceutical chemistry and synthetic chemistry. Compared with conventional methods, a direct asymmetric sulfonylation reaction with the fixation of sulfur dioxide represents an attractive strategy for the rapid assembly of chiral sulfones with enantiopurity. In this highlight, we survey recent exciting advances in asymmetric sulfonylation by using sulfur dioxide surrogates, and discuss asymmetric induction modes, reaction mechanisms, substrate scope and opportunities for further studies.

Stereoselective Palladium-Catalyzed Arylation of Exo-Glycals with Aryl Iodides

A novel methodology for the arylation of exo-glycals has been developed. A range of exo-glycals underwent reactions with aryl iodides in the presence of a palladium catalyst. The transformation proceeded in a stereoselective manner to afford Z-isomers. The developed transformation demonstrated excellent functional group tolerance.

Reading ADP-ribosylation signaling using chemical biology and interaction proteomics

ADP-ribose (ADPr) readers are essential components of ADP-ribosylation signaling, which regulates genome maintenance and immunity. The identification and discrimination between monoADPr (MAR) and polyADPr (PAR) readers is difficult because of a lack of suitable affinity-enrichment reagents. We synthesized well-defined ADPr probes and used these for affinity purifications combined with relative and absolute quantitative mass spectrometry to generate proteome-wide MAR and PAR interactomes, including determination of apparent binding affinities. Among the main findings, MAR and PAR readers regulate various common and distinct processes, such as the DNA-damage response, cellular metabolism, RNA trafficking, and transcription. We monitored the dynamics of PAR interactions upon induction of oxidative DNA damage and uncovered the mechanistic connections between ubiquitin signaling and ADP-ribosylation. Taken together, chemical biology enables exploration of MAR and PAR readers using interaction proteomics. Furthermore, the generated MAR and PAR interaction maps significantly expand our current understanding of ADPr signaling.

A three-component reaction of arynes, sodium sulfinates, and aldehydes toward 2-sulfonyl benzyl alcohol derivatives

A novel three-component reaction of arynes, sodium sulfinates, and aldehydes under mild reaction conditions is described. This transformation provides a direct synthetic approach to 2-sulfonyl benzyl alcohol derivatives, which could be rapidly converted to diverse arylsulfur compounds via the transformation of the corresponding hydroxyl groups. Various aryne precursors, sodium arenesulfinates, and aromatic aldehydes can be effectively converted to the desired products in 40-84% yields (29 examples).

One-Pot Preparation of (E)-α,β-Unsaturated Aldehydes by a Julia-Kocienski Reaction of 2,2-Dimethoxyethyl PT Sulfone Followed by Acid Hydrolysis

(E)-α,β-Unsaturated aldehydes were synthesized by the Julia-Kocienski reaction of 2,2-dimethoxyethyl 1-phenyl-1H-tetrazol-5-yl (PT) sulfone 3 with various aldehydes, followed by acid hydrolysis. The reaction could be carried out in one pot, and various (E)-α,β-unsaturated aldehydes were obtained in a short time and with high yields.