A mild CuI-catalyzed Glaser-type homo-coupling reaction using α,α-dibromo-β-dicarbonyl compounds as oxidants
摘要:
Exploration of alpha,alpha-dibromo-beta-dicarbonyl compounds as novel organic oxidants for the mild Cu(I)-catalyzed Glaser-type homo-coupling reaction has been achieved, which provides an alternatively efficient pathway for the construction of 1,3-conjugated structures. In addition, the mechanism of this reaction was investigated. (C) 2013 Elsevier Ltd. All rights reserved.
Oxidative bromination of ketones using ammonium bromide and oxone®
作者:Arun Kumar Macharla、Rohitha Chozhiyath Nappunni、Mahender Reddy Marri、Swamy Peraka、Narender Nama
DOI:10.1016/j.tetlet.2011.11.011
日期:2012.1
esters and α,α-dibromination of 1,3-diketones and β-keto esters without catalyst is reported using ammonium bromide as a bromine source and oxone® as an oxidant. The reaction proceeds at ambient temperature and yields range from moderate to excellent. Bromination of unsymmetrical ketones takes place at the less substituted α-position predominantly. Aromatisation of tetralones is also carried out with this
Solvent-free preparation of α,α-dichloroketones with sulfuryl chloride
作者:Dewei Tu、Juan Luo、Wengao Jiang、Qiang Tang
DOI:10.1016/j.tetlet.2021.153335
日期:2021.9
An efficient and facile method is reported for the synthesis of a series of α,α-dichloroketones. The direct dichlorination of methyl ketones and 1,3-dicarbonyls using an excess amount of sulfuryl chloride affords the corresponding -dichloro compounds in moderate to excellent yields. Moreover, the protocol features high yields, broad substrate scope, and simple reaction conditions without using any
2,2-Dibromo-1,3-diketones reacted with copper powder and olefin to give 4,5-dihydrofuran derivatives in a highly regioselective fashion.
2,2-二溴-1,3-二酮与铜粉和烯烃反应,以高度区域选择性的方式生成4,5-二氢呋喃衍生物。
Generation, electrocyclic ring opening, and unprecedented conversion of a 3-acylaminoazetinone into <i>cis</i>-3,4-disubstituted azetidinones
作者:Saul Wolfe、Stephen Ro、Zheng Shi
DOI:10.1139/v01-102
日期:2001.8.1
at sulfur, followed by fragmentation into a four-membered thietanone and a four-membered 3-acylaminoazetinone. The azetinone undergoes electrocyclicringopening, with a calculated half-life of 11 s at 40°C, to a trans-disubstituted vinyl isocyanate, but can be trapped by saturated, unsaturated allylic and benzylic alcohols to form 3,4-disubstituted azetidinones in which the cis- isomer predominates
A mild and environmentally acceptable synthetic protocol for chemoselective α-bromination of β-keto esters and 1,3-diketones
作者:Abu T. Khan、Papori Goswami、Lokman H. Choudhury
DOI:10.1016/j.tetlet.2006.02.075
日期:2006.4
A wide variety of unsubstituted β-ketoesters can be brominated chemoselectively to the corresponding α-monobromo-β-keto esters by using a combination of vanadium pentoxide, hydrogen peroxide and ammonium bromide in a biphasic system, dichloromethane–water at 0–5 °C. In addition, α-mono substituted β-ketoesters, cyclic β-keto-esters and 1,3-diketones can also be brominated selectively using the same