Highly Enantioselective Construction of Fused Pyrrolidine Systems That Contain a Quaternary Stereocenter: Concise Formal Synthesis of (+)‐Conessine

Abstract

No protecting groups were required in a concise and atom‐economical synthesis of the optically active tetracyclic pyrrolidine 3 under mild conditions. A highly diastereoselective Pauson–Khand reaction (1→2) was used to construct the compact tetracycle with its quaternary stereocenter. The stereoselectivity of the cycloaddition was affected by the substituent on the propargylic moiety.

Enabling the Cross-Coupling of Tertiary Organoboron Nucleophiles through Radical-Mediated Alkyl Transfer

“…Key contributions to highlight include Tsuji-Trost allylations, 6a Heck couplings, 6b Pauson-Khand cyclizations, 6c redox relay arylations, 6d and carbene C-H insertion reactions. 6e These examples are by no means comprehensive, but represent landmark catalytic approaches to the installation of challenging quaternary centers.…”

Copper‐catalyzed one‐pot synthesis of propargylamines via CH activation in PEG

“…The model reaction of benzaldehyde (1a), morpholine (2a) and phenylacetylene (3a) was conducted to screen the optimal reaction conditions and the results are listed in Table 1 [8][9][10][11][12].…”

A Low-Temperature Ammonium Ylid Rearrangement: Enhanced Reactivity Engendered by Rigidity

“…The key feature here is the rigidity of the bicyclic structure, which provides a preorganization of the endo transition state required for [2,3]-rearrangement. This fascinating extrapolation of the rich chemistry of cyclic ammonium ylid rearrangements is currently the focus of intense examination in our labs.…”