Enantioselective Synthesis of 1-Dihydrobenzazepines through Rh₂(II)-Catalyzed Cycloisomerization of 1,6-Enyne

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 13, 2025

The 1-dihydrobenzazepine skeleton has emerged as a privileged structural motif in bioactive molecules. However, due to lack of asymmetric methodology, access chiral 1-dihydrobenzazepines remained limited. Herein, we report the first intermolecular cycloisomerization benzo-fused enynes for synthesis via dirhodium catalysis. This methodology features high efficiency (up 98% yield), enantioselectivity 99% ee), and broad scope nucleophiles, including oxygen nucleophiles (alcohols, phenols, carboxylic acids) carbon (silyl enol ethers). Theoretical experimental mechanistic studies reveal that reaction pathway encompasses an cycloisomerization, which gives rise carbene containing donor–acceptor (D-A) cyclopropane moiety, followed by ring-opening process stereoselective nucleophilic attack external on cyclopropyl ring. Control experiments demonstrate pivotal role terminal group capped alkynyl substrates achieving good efficiency.

Language: Английский

Catalytic Generation of o-Quinone Dimethides by a Nondiazo Approach via Donor/Donor Platinum Carbenes

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: April 27, 2025

A platinum-catalyzed reaction of enynones with various dienophiles has been developed for the construction tetrahydronaphthalene derivatives, which undergo a Diels-Alder process platinum carbenes and o-quinone dimethide (o-QDM) intermediates. In this protocol, an alkoxy-substituted conjugated enynone is used as nondiazo carbene precursor generation o-QDMs, thereby extending methods available o-QDMs. The characterized by its high atom economy, diastereoselectivity, broad substrate scope.

Language: Английский

Rh-Catalyzed Cycloisomerization of 1,8-Enynes Initiated by C–C Activation: Diastereoselective Synthesis of Bicyclo[5.1.0]octene Systems

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 8894 - 8901

Published: May 12, 2025

Language: Английский