Phosphine-Catalyzed Diastereoselective Synthesis of β-Lactones from Disubstituted Ketenes and α-Chiral Oxyaldehydes
作者:Mukulesh Mondal、Shi Chen、Nabil Othman、Kraig A. Wheeler、Nessan J. Kerrigan
DOI:10.1021/acs.joc.5b00869
日期:2015.6.5
In this article we describe a catalytic procedure for the diastereoselective synthesis of β-lactones bearing two stereogenic centers, from disubstituted ketenes and α-chiral oxyaldehydes. Tri-n-butylphosphine was found to be the optimal catalyst in terms of effecting both good yield and diastereoselectivity (dr from 3:1 to 32:1 for 8 examples) in β-lactone formation. The major isomer of the β-lactone
在本文中,我们描述了一种催化方法,用于从双取代的烯酮和α-手性乙醛中非立体选择性合成带有两个立体生成中心的β-内酯。三Ñ丁基膦被发现是在(3 DR 1 8实施例:1〜32)都实现良好的收率非对映选择性和方面的最佳催化剂在β内酯的形成。在β内酯产品的主要异构体被确定为是反非对映体,它的形成是由极性Felkin-映模型合理化。通过31 P NMR光谱的反应监测表明了烯醇盐中间体参与反应机理。(+)-peloruside A合成子的短合成证明了该方法的实用性。
Staudinger et al., Helvetica Chimica Acta, 1923, vol. 6, p. 298
作者:Staudinger et al.
DOI:——
日期:——
Rhodium-Catalyzed Three-Component Reaction between Silylacetylene and Two Ketenes Leading to 1,3-Enynes Bearing a Carboxylic Ester Group via Double Insertion of Ketenes
作者:Kenichi Ogata、Itsuki Ohashi、Shin-ichi Fukuzawa
DOI:10.1021/ol301897h
日期:2012.8.17
The first cross-reaction between a terminal silylacetylene and two ketene molecules leading to 1,3-enynes bearing a carboxylic ester group via double insertion of ketenes is achieved using a cationic rhodium complex catalyst. This reaction is applicable for various symmetrical and unsymmetrical ketenes with good stereoselectivities.
GRZEGORZEWSKA U.; LEPLAWY M.; REDLINSKI A., ROCZ. CHEM. <ROCH-AC>, 1975, 49, NO 11, 1859-1863