Enantioselective, cyclopentene-forming annulations via NHC-catalyzed benzoin-oxy-cope reactions

被引:270
作者
Chiang, Pei-Chen [1 ]
Kaeobamrung, Juthanat [1 ]
Bode, Jeffrey W. [1 ]
机构
[1] Univ Calif Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 USA
关键词
H ACTIVATION/COPE REARRANGEMENT; DIELS-ALDER REACTIONS; ALPHA; BETA-UNSATURATED ALDEHYDES; STEREOSELECTIVE-SYNTHESIS; GAMMA-BUTYROLACTONES; FUNCTIONALIZED CYCLOPENTENES; ACTIVATED CARBOXYLATES; NUCLEOPHILIC CARBENES; CONJUGATE ADDITION; ENALS;
D O I
10.1021/ja0705543
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Chiral N-heterocyclic carbene catalysts generated from triazolium salts promote the cyclopentene-forming annulation of alpha,beta-unsaturated aldehydes and 4-oxoenoates with excellent levels of enantioinduction and preference for the cis-1,3,4-trisubstituted cyclopentene diastereomer. Although the observed products could arise by conjugate additions of catalytically generated homoenolates, our mechanistic and stereochemical investigations strongly support a novel reaction manifold featuring an intermolecular crossed-benzoin reaction and an NHC-catalyzed oxy-Cope rearrangement.
引用
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页码:3520 / +
页数:3
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