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。
A Selective Direct Aldol Reaction in Aqueous Media Catalyzed byZinc-Proline
The Zn–proline complex is shown to catalyze the aldolreaction of acetone and a wide range of arenecarbaldehydes in aqueous media, accepting even deactivated arenecarbaldehydes such as methoxybenzaldehydes in good yields. Enantiomeric excesses of up to 56 % could be obtained with 5 mol-% of the catalyst at room temperature, and up to 66 %
Strategy for the Synthesis of Pyridazine Heterocycles and Their Derivatives
作者:Hassen Bel Abed、Oscar Mammoliti、Omprakash Bande、Guy Van Lommen、Piet Herdewijn
DOI:10.1021/jo400989q
日期:2013.8.16
The first synthesis of novel fused pyridazines has been realized starting from 1,3-diketones involving a Diaza–Wittig reaction as a key step. A convenient strategy was elaborated to access versatile pyridazinederivatives allowing the variation of substituents at position 6 of the heterocyclic ring. In a first part, pyridazines bearing an ester group were synthesized as a model to evaluate the methodology
The application of deep eutectic solvents has been demonstrated for the first time in promiscuous lipase-catalysed aldol reactions. The model reaction between 4-nitrobenzaldehyde and acetone was examined in depth, with excellent compatibility being found between porcine pancreas lipase and choline chloride/glycerol mixtures for the formation of the aldol product in high yields. The system was compatible