Multi-component multi-functionalization reactions involving active intermediates are powerful tools for rapidly generating a wide array of compounds. Metal carbynoids, with their distinct reactivity, hold great promise for developing synthetic methodologies. However, their application in catalytic transfer reactions has been hindered by the limited availability of suitable precursors. In this study, we investigate the catalytic potential of α-halo Rh-carbenes, leveraging the concept of metal carbynoids in multi-functionalization reactions. Through a chiral phosphoric acid-catalyzed asymmetric trifunctionalization, we have developed a method for synthesizing a variety of chiral α-cyclic ketal β-amino esters with high yields and excellent enantioselectivity. Our extensive experimental and computational studies reveal that α-halo Rh-carbenes exhibit carbynoid properties, which facilitate the transformation into functionalized Fischer-type Rh-carbenes through the decomposition of the C-halo bond.

Phosphine catalysis generally relies on the potential of carbanion-phosphonium zwitterions that are generated via nucleophilic addition of phosphine catalyst to electrophilic reactants. Consequently, structural modification of zwitterions using distinct electrophilic reactants has emerged as a prominent strategy to enhance catalysis diversity. Herein, we present an alternative strategy that utilizes AgF additive to expand phosphine catalysis. We find that AgF can readily transform the canonical carbanion–phosphonium zwitterion into silver enolate–fluorophosphorane intermediate, eventually furnishing a P(III)/P(V) catalytic cycle. This strategy has been successfully applied to the phosphine-catalyzed reaction of 2-substituted allenoate and imine, resulting in the transition from Kwon [4 + 2] cycloaddition to [3 + 2] cycloaddition. This [3 + 2] cycloaddition features remarkable diastereoselectivity, high yield, and broad substrate scope. Experimental and computational studies have validated the proposed mechanism. Given the prevalence of carbanion–phosphonium zwitterions in phosphine catalysis, this AgF-assisted strategy is believed to hold significant potential for advancing P(III)/P(V) catalysis.

The synthesis of ester derivatives represents one of the most significant and fundamental tasks in modern organic chemistry, and numerous methods have been developed in both academic and industrial contexts. Among these, alkoxycarbonyl radical‐mediated functionalization strategies have emerged as a highly efficient and versatile tool for the synthesis of these compounds. Despite the significant advancements in recent years, the radical‐induced enantioselective alkoxycarbonylation reaction remains largely unexplored. Herein, a highly enantioselective alkoxycarbonyl‐lactonization of alkenes is reported through a photoredox/copper dual‐catalyzed alkoxycarbonyl radical addition/cyclization reaction. With this approach, a diverse array of ester‐substituted chiral γ‐butyrolactones bearing a quaternary stereocenter can be readily obtained in high yields and with excellent enantioselectivities under mild reaction conditions. This versatile method shows good substrate tolerance for primary, secondary, and tertiary alcohol derivatives while maintaining exceptional stereochemical control.