MnO<sub>2</sub> as a terminal oxidant in Wacker oxidation of homoallyl alcohols and terminal olefins
作者:Rodney A. Fernandes、Gujjula V. Ramakrishna、Venkati Bethi
DOI:10.1039/d0ob01344g
日期:——
PdCl2/CrO3/HCl produced α,β-unsaturated ketonesfrom homoallyl alcohols, the present method provided orthogonally the β-hydroxy-methyl ketones. No overoxidation or elimination of benzylic and/or β-hydroxy groups was observed. The method could be extended to the oxidation of simple terminalolefins as well, to methyl ketones, displaying its versatility. An application to the regioselective synthesis of gingerol is
the protection of alcohols as THP, THF, and EE ethers as well as the cleavage of THP, THF, and EE ethers to the corresponding alcohols. They could be applied to 1°, 2° and 3° alcohols, phenol and acid-labile alcohols. Both ATPB and catalyst A are excellent catalysts in the present study. It needed only 1×10−2–1.25×10−2 mol equiv. of the polymer-supported catalyst A in the reactions.
Kinetic resolution of aliphatic acyclic β-hydroxyketones by recombinant whole-cell Baeyer–Villiger monooxygenases—Formation of enantiocomplementary regioisomeric esters
作者:Jessica Rehdorf、Alenka Lengar、Uwe T. Bornscheuer、Marko D. Mihovilovic
DOI:10.1016/j.bmcl.2009.05.014
日期:2009.7
substrates in the enzymatic kinetic and regioselective Baeyer–Villiger oxidation catalyzed by 12 Baeyer–Villigermonooxygenases from different bacterial origin. Excellent enantioselectivities (E >100) could be observed with 4-hydroxy-2-ketones. After acyl migration, the ester undergoes hydrolysis followed by the formation of optically active 1,2-diols. Furthermore, resolution of 5-hydroxy-3-ketones gave
A highly chemoselective Mukaiyama aldol reaction of saturated aldehyde over unsaturated aldehyde with enol tris(2,6-diphenylbenzyl)silyl ether
作者:Seiji Shirakawa、Keiji Maruoka
DOI:10.1016/s0040-4039(02)00036-9
日期:2002.2
An exceedingly high chemoselective Mukaiyamaaldolreaction of saturated aldehydes in the presence of unsaturated aldehydes (benzaldehyde and α,β-enals) has been realized for the first time by using the structurally unique enol tris(2,6-diphenylbenzyl)silyl ether under the influence of BF3·OEt2 as a Lewisacid. Among unsaturated aldehydes, benzaldehyde is found to be more reactive than α,β-enals. The
在不饱和醛(苯甲醛和α,β-烯醛)存在下,饱和醛的极高化学选择性的Mukaiyama aldol反应已首次通过在结构上使用结构独特的烯醇三(2,6-二苯基苄基)甲硅烷基醚来实现。 BF 3 ·OEt 2作为路易斯酸的影响 在不饱和醛中,发现苯甲醛比α,β-烯醛更具反应性。烯醇三(2,6-二苯基苄基)甲硅烷基醚的结构独特性可以通过X射线晶体学以及1 H和13 C NMR光谱来观察。
Synthesis of 1,3-Dicarbonyl Compounds by the Oxidation of 3-Hydroxycarbonyl Compounds with Corey-Kim Reagent
A new method for the preparation of various 1,3-dicarbonyl compounds is described. Oxidation of 3-hydroxycarbonyl compounds without substituent at C-2 position by the Corey-Kim reagent (N-chlorosuccinimide-dimethyl sulfide) afforded the stable dimethylsulfonium methylides, which on reductive desulfurization by zinc-acetic acid furnished the 1,3-dicarbonyl derivatives.On the other hand, the same treatment of 2-mono-, or 2,2-disubstituted 3-hydroxy-carbonyl compounds gave directly the corresponding 1,3-dicarbonyl analogous,respectively.