Origin of the E/Z Selectivity in the Synthesis of Tetrasubstituted Olefins by Wittig Reaction of α-Fluorophosphonium Ylides: An Explanation for the Low Stereoselectivity Observed in Reactions of α-Alkoxy Aldehydes

被引：9

作者：

Depre, Dominique ^{[1
]}

Vermeulen, Wim A. A. ^{[1
]}

Lang, Yolande ^{[1
]}

Dubois, Jean ^{[1
]}

Vandevivere, Jan ^{[1
]}

Vandermeersch, Jeremy ^{[1
]}

Huang, Longchuan ^{[1
]}

Robiette, Raphael ^{[2
]}

机构：

[1] Janssen Pharmaceut Co Johnson & Johnson, API Small Mol Dev, Turnhoutseweg 30, B-2340 Beerse, Belgium

[2] Catholic Univ Louvain, Inst Condensed Matter & Nanosci, Pl Louis Pasteur 1,Box L4 01 02, B-1348 Louvain, Belgium

来源：

ORGANIC LETTERS | 2017年 / 19卷 / 06期

关键词：

HYDROGEN-BONDS; STEREOCHEMISTRY; MECHANISM;

D O I：

10.1021/acs.orglett.7b00344

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

A series of tetrasubstituted fluoroalkenes were synthesized in good yield and high E/Z selectivity (up to 96/4) by Wittig reaction between alpha-heterosubstituted ketones and alpha-fluorophosphonium ylides. A detailed study of factors that control stereoselectivity in these reactions shows that stereo-selectivity is the result of stabilizing CH center dot center dot center dot F and N center dot center dot center dot C=O interactions in the addition TS leading to the E isomer. This analysis provides a rationale for the observed decrease in selectivity for reactions of stabilized ylides with alpha-alkoxy aldehydes.

引用

页码：1414 / 1417

页数：4

共 18 条

[1]

Abell A.D., 2004, Organophosphorus Reagents, P99

[2]

BESTMANN HJ, 1983, TOP CURR CHEM, V109, P85

[3] Unequivocal Experimental Evidence for a Unified Lithium Salt-Free Wittig Reaction Mechanism for All Phosphonium Ylide Types: Reactions with β-Heteroatom-Substituted Aldehydes Are Consistently Selective for cis-Oxaphosphetane-Derived Products [J].