Palladium-Catalyzed Multicomponent Assembly of (Z)-Alkenylborons via Carbopalladation/Boronation/Retro-Diels-Alder Cascade Reaction

Palladium-Catalyzed Enantioselective Synthesis of P(V)-Stereogenic Compounds via Desymmetric Annulation of Prochiral Phosphinamides and Aryl Iodides

The enantioselective synthesis of P(V)-stereogenic compounds has emerged as an interesting research topic primarily due to their significant biological activity and broad application prospects. Herein, we disclose a method for the construction of P(V)-stereogenic compounds from prochiral phosphinamides and aryl iodides via palladium- and chiral norbornene-catalyzed desymmetric annulation. The P(V)-stereogenic compounds were formed with a broad scope with excellent enantiomeric excesses. It is noteworthy that the synthetic value of this procedure was proven by a variety of transition metal-catalyzed cross-coupling reactions using the C-Br bond on the product as a versatile linchpin electrophile.

Palladium-Catalyzed Dual C-H Arylation/Cyclization Reaction of Iodoferrocenes with ortho-Bromobenzamides for the Construction of Arylated Isoquinolone-Fused Ferrocenes

We reported a palladium/norbornene-catalyzed dual intermolecular C-H arylation/intramolecular cyclization reaction of iodoferrocenes with ortho-bromobenzamides, enabling the formation of arylated isoquinolone-fused ferrocenes in a straightforward and effective manner. This method has a broad substrate scope and good functional group compatibility, while the gram-scale reaction demonstrates the practicality of this method.

Solvent-Controlled Enantiodivergent Construction of P(V)-Stereogenic Molecules via Palladium-Catalyzed Annulation of Prochiral N-Aryl Phosphonamides with Aromatic Iodides

In this work, we describe an efficient and modular method for enantiodivergent accessing P(V)-stereogenic molecules by utilizing the catalytic atroposelective Catellani-type C-H arylation/desymmetric intramolecular N-arylation cascade reaction. The enantioselectivity of this protocol was proved to be tuned by the polarity of the solvent, thus providing a wide range of both chiral P(V)-stereogenic enantiomers in moderate to good yields with good to excellent enantiomeric excesses. Noteworthy is that the strategy developed herein represents an unprecedented example of solvent-dictated inversion of the enantioselectivity of P(V)-stereogenic compounds.

A switch strategy for the synthesis of C4-ethylamine indole and C7-aminoindoline via controllable carbon elimination

Controllable β-carbon elimination to extrude norbornene remains a long-standing challenge in palladium and norbornene chemistry. Herein, this manuscript describes a switchable synthesis of biologically active C4-ethylaminoindole and C7-aminoindoline scaffolds by controlling β-carbon elimination, utilizing aziridine as a C-H ethylamination reagent through a C-N bond cleavage reaction. Furthermore, the protecting groups of the product can be easily removed, offering an unusual method for the synthesis of dopamine receptor agonists.

Cobalt catalyzed practical hydroboration of terminal alkynes with time-dependent stereoselectivity

Stereodefined vinylboron compounds are important organic synthons. The synthesis of E-1-vinylboron compounds typically involves the addition of a B-H bond to terminal alkynes. The selective generation of the thermodynamically unfavorable Z-isomers remains challenging, necessitating improved methods. Here, such a proficient and cost-effective catalytic system is introduced, comprising a cobalt salt and a readily accessible air-stable CNC pincer ligand. This system enables the transformation of terminal alkynes, even in the presence of bulky substituents, with excellent Z-selectivity. High turnover numbers (>1,600) and turnover frequencies (>132,000 h-1) are achieved at room temperature, and the reaction can be scaled up to 30 mmol smoothly. Kinetic studies reveal a formal second-order dependence on cobalt concentration. Mechanistic investigations indicate that the alkynes exhibit a higher affinity for the catalyst than the alkene products, resulting in exceptional Z-selective performance. Furthermore, a rare time-dependent stereoselectivity is observed, allowing for quantitative conversion of Z-vinylboronate esters to the E-isomers.