C-Quaternary Vinylglycinols by Metal-Catalyzed Cyclization of Allylic Bistrichloroacetimidates

被引:20
作者
Klimovica, Kristine [1 ]
Grigorjeva, Liene [1 ]
Maleckis, Ansis [1 ]
Popelis, Juris [1 ]
Jirgensons, Aigars [1 ]
机构
[1] Latvian Inst Organ Synth, LV-1006 Riga, Latvia
关键词
amino alcohols; Lewis acids; palladium; cyclization; regioselectivity; VINYL AMINO-ACIDS; ASYMMETRIC-SYNTHESIS; ENANTIOSELECTIVE SYNTHESIS; ALPHA-VINYL; STEREOSELECTIVE ADDITION; REARRANGEMENT; DERIVATIVES; REAGENTS;
D O I
10.1055/s-0031-1289537
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
Bistrichloroacetimidates derived from 2-substituted but-2-ene-1,4-diols are transformed into 4-substituted 4-vinyloxazolines in high yields and excellent regioselectivities when Lewis acids AlCl3, FeCl3, TMSOTf, BF3 center dot OEt2, and AgBF4 are used as catalysts as well as with the Pd(PPh3)(2)Cl-2/AgBF4 catalytic system. Lower regioselectivity is achieved with a neutral PdCl2(MeCN)(2) catalyst and this could be a consequence of a switch to a competitive but less selective reaction mechanism. It is demonstrated that 4-substituted 4-vinyloxazolines can be efficiently transformed to N-Boc-protected C-quaternary vinylglycinols in a one-pot procedure.
引用
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页码:2849 / 2851
页数:3
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