A simple and practical synthesis of ynones directly from readily available aldehydes was developed for the first time under mild reaction conditions via a Rh(III)- or Ir(III)-catalyzed formyl C-H bondactivation.
enantioselective decarboxylative [4 + 2]-annulation of ethynyl benzoxazinanones with azlactones has been developed under cooperative copper and bifunctional tertiary aminourea catalysis. This direct and modular approach combines dipolar copper-allenylidene intermediates with azlactone enolates and allows for the synthesis of α-quaternary α-acylaminoamides as a single diastereomer generally in high yields
An efficient three‐component coupling (TCC) reaction toward a variety of 3‐aminoindoline and 3‐aminoindole derivatives has been developed. This cascade transformation proceeds via the copper‐catalyzed coupling reaction between 2‐aminobenzaldehyde, a secondary amine, and an alkyne leading to a propargylamine intermediate which, under the reaction conditions, undergoes cyclization into the indoline core
4-dienylation/Michael addition/π–σ–π isomerization/allylic alkylation. A broad array of enantioenriched architectures having fused and spirocyclic frameworks are constructed in moderate to excellent yields and stereoselectivity. Notably, the intrinsic intramolecular Diels–Alder reaction pattern of the dienylated intermediates is well reversed via Pd(0)−π–Lewis base catalysis.
One-Pot Phosphine-Catalyzed Syntheses of Quinolines
作者:San Khong、Ohyun Kwon
DOI:10.1021/jo3015825
日期:2012.9.21
In this study we developed an efficient one-pot procedure for the preparation of 3-substituted and 3,4-disubstituted quinolines from stable starting materials (activated acetylenes reacting with o-tosylamidobenzaldehydes and o-tosylamidophenones, respectively) under mild conditions. The reaction appears to operate under a general base catalysis mechanism, instigated by the beta-phosphonium enoate alpha-vinyl anion generated in situ through nucleophilic addition of PPh3 to the activated alkyne. Michael addition of the deprotonated tosylamides to the activated alkynes and subsequent rapid aldol cyclization led to the formation of labile N-tosyldihydroquinoline intermediates. Driven by aromatization, detosylation of the dihydroquinoline intermediates occurred readily in the presence of dilute aqueous HCl to give the final quinoline products.