Unprecedented Catalytic Asymmetric Reduction of N−H Imines
摘要:
Addition of lithium bis(trimethylsilyl)amide to perfluorinated ketones 1a-j affords (E)-N-TMS-ketimines 2a-j that are reduced in situ to afford racemic perfluoromethylated amine hydrochloride salts 3a-j in 54-97% yields. Solvolysis of the N-Si bond in MeOH leads to formation of bench-stable, isolable N-H imine Z/E isomer mixtures along with a methanol adduct. Enantioselective reduction of these three-component mixtures provides the first catalytic asymmetric synthesis of trifluoromethylated amines in 72-95% yields and 75-98% ee.
Palladium-catalyzed fluoroacylation of (Hetero)arylboronic acid with fluorothioacetates at ambient temperature
摘要:
A palladium-catalyzed fluoroacylation of (hetero)aryl boronic acid with the fluorothioacetates is described at ambient temperature. A variety of aryl, and heteroaryl boronic acids are compatible in the reaction, affording the corresponding fluoroalkyl ketones in moderate to good yields. Further late-stage di-, and trifluoroacylation of drug molecule clofibrate and estrone demonstrated the synthetic practicability of this protocol.2009 Elsevier Ltd. All rights reserved. (C) 2020 Elsevier Ltd. All rights reserved.
Trifluoromethyl group in the synthesis of heterocyclic compounds: New and efficient synthesis of 3-aryl-4-aminocinnolines
作者:Alexander S. Kiselyov
DOI:10.1016/0040-4039(95)00005-w
日期:1995.2
A novel base induced transformation of hydrazones 3a-f derived from trifluoromethylaryl ketones and arylhydrazines was found to produce 3-aryl-4-aminocinnolines 4a-g in 52-75% yield. The initial step of the reaction is believed to involve abstraction of Hf from hydrazone.