Rhodium-catalyzed hydroaroylation of α,β-unsaturated esters using aroyl chlorides and Et2MeSiH
摘要:
Hydroaroylation of methyl acrylate 2a to give the alpha-aroyl esters 4 took place in the three-component reaction of 2a, aroyl chlorides 1, and Et2MeSiH in the presence of 1 mol % of [Rh(cod)(PR3)2]OTf (cod = 1,5-cyclooctadiene, OTf = OSO2CF3, R = Ph (3a), OPh (3b)) in CH2Cl2. GC and H-1 NMR investigation revealed that the rhodium-catalyzed hydroaroylation proceeds via two successive transformations, that is, hydrosilylation of 2a to afford silyl enol ether 5a followed by C-C bond formation between 5a and 1a. (C) 2013 Elsevier Ltd. All rights reserved.
An efficientazidation of 1,3-dicarbonylcompounds led to tertiary azides in the presence of tetrabutylammoniumiodide (TBAI). TBAI is used as a pre-catalyst along with aq. tert-butyl hydroperoxide (TBHP) as an oxidant in aqueous medium. This operationally simple, practical, mild and green method provides an opportunity to synthesize a variety of azidated -keto esters, amides, and ketones in good yields
在四丁基碘化铵 (TBAI) 存在下,1,3-二羰基化合物的有效叠氮化反应生成叔叠氮化物。TBAI 与 aq 一起用作预催化剂。叔丁基过氧化氢 (TBHP) 作为水性介质中的氧化剂。这种操作简单、实用、温和且绿色的方法为以良好的收率合成各种叠氮化酮酯、酰胺和酮提供了机会。