Simple preparation of trans-epoxides via ylide intermediates

被引：10

作者：

Aggarwal, VK ^{[1
]}

Aragoncillo, C ^{[1
]}

Winn, CL ^{[1
]}

机构：

[1] Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England

来源：

SYNTHESIS-STUTTGART | 2005年 / 08期

关键词：

asymmetric catalysis; diazo compounds; epoxidations; sulfur ylides; epoxides;

D O I：

10.1055/s-2004-834885

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

A practical route to epoxides with control of the relative and absolute stereochemistry has been developed. allowing epoxides to be readily prepared on a 20 mmol scale by generating the reactive intermediate (the diazo compound) in situ from benzaldehyde tosylhydrazone sodium salt. In this paper. we describe the optimum conditions for three procedures to obtain the desired racemic and enantiomerically enriched epoxides (Scheme 1). High diastereoselectivities (98-100;) and very high yields of epoxide were obtained. Asymmetric epoxidation was carried out using the chiral camphor-derived [2.2.1] bicyclic sulfide 4 and the desired epoxide was obtained with excellent enantioselectivity (94%).

引用

页码：1378 / 1382

页数：5

共 24 条

[1]

Aggarwal V.K., 1999, Comprehensive Asymmetric Catalysis II, P679

[2] Catalytic, asymmetric sulfur ylide-mediated epoxidation of carbonyl compounds: Scope, selectivity, and applications in synthesis [J].

Aggarwal, VK ;

Winn, CL .

ACCOUNTS OF CHEMICAL RESEARCH, 2004, 37 (08) :611-620

[3]

Aggarwal VK, 1998, SYNLETT, P329

[4] The complexity of catalysis: origins of enantio- and diastereocontrol in sulfur ylide mediated epoxidation reactions [J].

Aggarwal, VK ;

Richardson, J .

CHEMICAL COMMUNICATIONS, 2003, (21) :2644-2651

[5] A new protocol for the in situ generation of aromatic, heteroaromatic, and unsaturated diazo compounds and its application in catalytic and asymmetric epoxidation of carbonyl compounds. Extensive studies to map out scope and limitations, and rationalization of diastereo- and enantioselectivities [J].

Aggarwal, VK ;

Alonso, E ;

Bae, I ;

Hynd, G ;

Lydon, KM ;

Palmer, MJ ;

Patel, M ;

Porcelloni, M ;

Richardson, J ;

Stenson, RA ;

Studley, JR ;

Vasse, JL ;

Winn, CL .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (36) :10926-10940

[6] Synthesis of epoxides from aldehydes and tosylhydrazone salts catalysed by triphenylarsine:: complete trans selectivity for all combinations of coupling partners [J].

Aggarwal, VK ;

Patel, M ;

Studley, J .

CHEMICAL COMMUNICATIONS, 2002, (14) :1514-1515

[7] Catalytic asymmetric epoxidation of aldehydes. Optimization, mechanism, and discovery of stereoelectronic control involving a combination of anomeric and Cieplak effects in sulfur ylide epoxidations with chiral 1,3-oxathianes [J].

Aggarwal, VK ;

Ford, JG ;

Fonquerna, S ;

Adams, H ;

Jones, RVH ;

Fieldhouse, R .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1998, 120 (33) :8328-8339

[8] A novel catalytic cycle for the synthesis of epoxides using sulfur ylides [J].

Aggarwal, VK ;

AbdelRahman, H ;

Fan, L ;

Jones, RVH ;

Standen, MCH .

CHEMISTRY-A EUROPEAN JOURNAL, 1996, 2 (08) :1024-1030

[9] Direct asymmetric epoxidation of aldehydes using catalytic amounts of enatiomerically pure sulfides [J].

Aggarwal, VK ;

Ford, JG ;

Thompson, A ;

Jones, RVH ;

Standen, MCH .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1996, 118 (29) :7004-7005

[10]

Aggarwal VK, 2001, ANGEW CHEM INT EDIT, V40, P1430, DOI 10.1002/1521-3773(20010417)40:8<1430::AID-ANIE1430>3.0.CO

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