Cycloaddition of trifluoromethyl azafulvenium methides: synthesis of new trifluoromethylpyrrole-annulated derivatives

TETRAHEDRON LETTERS

卷:51

Article

Nunes, Claudio M.¹  Silva, Manuela Ramos²  Beja, Ana Matos²  Fausto, Rui¹  Pinho e Melo, Teresa M. V. D.¹ 

[1] Univ Coimbra, Dept Chem, P-3004535 Coimbra, Portugal

[2] Univ Coimbra, Dept Phys, P-3004516 Coimbra, Portugal

关键词: Trifluoromethylpyrroles;    1,3-Dipoles;    1,7-Dipoles;    Azafulvenium methides;    Azomethine ylides;    [8 pi+2 pi] Cycloaddition;    1,3-Dipolar cycloaddition;    1,7-Electrocyclization;    Microwave;   

DOI  :  10.1016/j.tetlet.2009.11.033

来源: Elsevier

【 摘 要 】

The chemistry of trifluoromethyl azafulvenium methides was explored leading to a new route to trifluoromethylpyrrole-annulated systems. The first evidence of azafulvenium methides acting as 1,3-dipoles is reported. These azafulvenium methides showed site selectivity in the reaction with strong electron-deficient dipolarophiles leading exclusively to 1,3-cycloadducts. In the cycloaddition with less-activated dipolarophiles 1,7-cycloadducts resulting from [8 pi+2 pi] cycloaddition are also formed. FMO analysis of the cycloaddition reactions allowed the rationalization of the observed selectivity. (C) 2009 Elsevier Ltd. All rights reserved.

【 授权许可】

Free