Hot water-promoted cyclopropylcarbinyl rearrangement facilitates construction of homoallylic alcohols
作者:Pei-Fang Li、Cheng-Bo Yi、Jin Qu
DOI:10.1039/c5ob00305a
日期:——
H2O–1,4-dioxane and without an additional catalyst, the rearrangements of various types of cyclopropylcarbinols were attempted. It was found that the reactions generally gave homoallylic alcohols in good to very high chemical yields. Rearrangements of bicyclic or tricyclic cyclopropylcarbinols readily gave the desired ring-expanded cyclic homoallylic alcohols which are difficult to synthesize by other
enones from olefins is described. The reaction was performed under visible-light irradiation in the presence of molecular oxygen and a photocatalyst. The reaction proceeded with various types of trisubstituted olefins to give enones in good yields with high regioselectivity. In particular, oxygen- and nitrogen-containing functional groups, heteroaromatic rings, and cyclopropanes were tolerated. Mechanistic
An efficient and stereoselective synthesisi of homoallylic alcohols via nickel-catalysed coupling of 5-alkyl-2,3-dihydrofurans with Grignard reagents
作者:Sjoerd Wadman、Richard Whitby、Clive Yeates、Philips Kocienski、Kelvin Cooper
DOI:10.1039/c39870000241
日期:——
The low-valent nickel-catalysedcoupling of Grignardreagents with 5-alkyl-2,3-dihydrofurans is an efficient and stereoselective method for synthesising homoallylicalcohols provided appropriate care is taken in the workup.
A stereoselective synthesis of trisubstituted alkenes. Part 1. Nickel-catalysed coupling of Grignard reagents with 5-alkyl-2,3-dihydrofurans
作者:Philip J. Kocieński、Martin Pritchard、Sjoerd N. Wadman、Richard J. Whitby、Clive L. Yeates
DOI:10.1039/p19920003419
日期:——
5-Alkyl-2,3-dihydrofurans 3a–j prepared by the alkylation of 5-lithio-2,3-dihydrofuran 2 with primary alkyl bromides and iodides, undergo Ni0-catalysed coupling with Grignardreagents to give homoallylicalcohols. The yield and stereoselectivity depend on the structure of the Grignardreagent with the best results being obtained with long chain primary Grignardreagents and Grignardreagents lacking
通过5-lithio-2,3-二氢呋喃2与伯烷基溴化物和碘化物的烷基化反应制得的5-烷基-2,3-二氢呋喃3a – j与Niignyard试剂进行Ni 0催化偶联,得到均丙醇。产率和立体选择性取决于格氏试剂的结构,使用长链伯氏格氏试剂和缺少β-氢的格氏试剂(Me,Ph,Me 3 SiCH 2)可获得最佳结果。5-(1-羟基烷基)-2,3-二氢呋喃20和21是偶联反应的不良底物。提出了用于偶合以及竞争性还原和异构化反应的机理。
Enantioselective fluorination of homoallylic alcohols enabled by the tuning of non-covalent interactions
作者:Jaime A. S. Coelho、Akira Matsumoto、Manuel Orlandi、Margaret J. Hilton、Matthew S. Sigman、F. Dean Toste
DOI:10.1039/c8sc02223b
日期:——
The study of the enantioselective fluorination of homoallylicalcohols via chiral anion phase transfer (CAPT) catalysis using an in situ generated directing group is described. Multivariate correlation analysis, including designer π-interaction derived parameters, revealed key structural features affecting the selectivity at the transition state (TS). Interpretation of the parameters found in the model