SmI2-Promoted Oxidation of Aldehydes in the Presence of Electron-Rich Heteroatoms
摘要:
[GRAPHICS]The Evans-Tishchenko reaction provides an efficient and practical solution for the oxidation of aldehydes possessing sensitive electron-rich heteroatoms to the corresponding esters. Careful selection of the sacrificial beta-hydroxy ketone provides considerable subsequent flexibility to access the desired carboxylic acid.
By judicious choice of the counter anions in the vanadyl catalysts, we can achieve β-hydroxylated and t-butyl peroxylated carbonylation of styrenes by aromatic 1° and 2° alkyl aldehydes in a complementary manner.
Bis(amido)magnesium mediated aldol additions: first structural characterisation of an amidomagnesium aldolate intermediate
作者:John F. Allan、Kenneth W. Henderson、Alan R. Kennedy
DOI:10.1039/a903784e
日期:——
Bis(hexamethyldisilazido)magnesium has successfully been used to mediate aldol additions of selected ketones and aldehydes in hydrocarbon media, and the structure of an intermediate amido(aldolate), [(Me3Si)2NMg[µ-OC(Me)- ButCH2C(But)=O]}2] 17, produced by the self-coupled reaction of pinacolone has been characterised by X-ray crystallography.
Anti-selective and regioselective aldol addition of ketones with aldehydes using MgI2 as promoter
作者:Han-Xun Wei、Richard L. Jasoni、Huawu Shao、Jiali Hu、Paul W. Paré
DOI:10.1016/j.tet.2004.09.098
日期:2004.12
The firstexample of a direct aldehyde–ketone coupling using the secondary amine piperidine as base in the presence of MgI2 to generate high selectivity of anti-aldol products from unmodified ethyl ketones in high yield is reported. The coupling reactions were carried out in a one-pot reaction by mixing four reaction components at room temperature. In the case of unsymmetrical ketones, addition was
Directed Reductive Amination of β-Hydroxy-ketones: Convergent Assembly of the Ritonavir/Lopinavir Core
作者:Dirk Menche、Fatih Arikan、Jun Li、Sven Rudolph
DOI:10.1021/ol062715y
日期:2007.1.1
3-syn-amino alcohols (6) is reported. The operationally simple protocol uses Ti(iOPr)4 for coordination of the intermediate imino alcohol (5) and PMHS as the reducing agent. The method was expanded to an asymmetric aldol reductive amination sequence to allow a highly convergentsynthesis of the hydroxy-amine core of the HIV-protease inhibitors ritonavir and lopinavir. [reaction: see text].
The Chemistry of Trichlorosilyl Enolates. Aldol Addition Reactions of Methyl Ketones
作者:Scott E. Denmark、Robert A. Stavenger
DOI:10.1021/ja001023g
日期:2000.9.1
observed in this uncatalyzed aldol process. The aldol additions are dramatically accelerated by the addition of catalytic quantities of chiral phosphoramides, particularly one derived from N,N‘-dimethylstilbene-1,2-diamine. In this catalyzed mode, good to high enantioselectivities are obtained with a variety of achiral trichlorosilyl enolates and aldehydes. When either partner bears a stereogenic center