X=Y-ZH compounds as potential 1,3-dipoles. Part 64: Synthesis of highly substituted conformationally restricted and spiro nitropyrrolidines via Ag(I) catalysed azomethine ylide cycloadditions

TETRAHEDRON

卷:64

Article

Grigg, Ronald¹  Kilner, Colin¹  Sarker, Mohammed A. B.¹  de la Cierva, Cecilia Orgaz¹  Dondas, H. Ali¹ 

[1] Univ Leeds, Sch Chem, MIDAS Ctr, Leeds LS2 9JT, W Yorkshire, England

关键词: metallo-azomethine ylides;    cycloaddition;    silver oxide;    nitroolefins;    pyrrolidines;    spirocycles;   

DOI  :  10.1016/j.tet.2008.05.132

来源: Elsevier

【 摘 要 】

13-Dipolar reactions of imines of both acyclic and cyclic alpha-amino esters with a range of nitroolefins using a combination of AgOAc or Ag(2)O with NEt(3) are described. In most cases the reactions were highly regio and stereospecific and endo-cycloadducts were obtained in good yield. However, in a few cases the initially formed cycloadducts underwent base catalysed epimerisation. The stereochemistry of the cycloadducts was assigned from NOE data and established unequivocally in several cases by X-ray crystallography. (C) 2008 Elsevier Ltd. All Fights reserved.

【 授权许可】

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