yield. The annulation reactions are highly regio- and stereoselective and lead to the formation of exo-Ph-P substituted products exclusively. Reduction of the resulting bicyclic phosphineoxides by phenylsilane gives the corresponding phosphines with complete retention of configuration at P. Application of this annulation procedure to acyclic allylic substrates leads to the corresponding monocyclic
Alkylation and cyclopentannulation of phospholene derivatives
作者:Zbigniew Pakulski、Renata Kwiatosz、K. Michał Pietrusiewicz
DOI:10.1016/j.tet.2004.12.004
日期:2005.2
The deprotonation of 1-phenyl-3-phospholene I-oxide. I-sulfide or I-borane with I or 2 equiv of LDA, followed by quenching, with electrophiles gave a range of 2-mono- or 2.5-disubstituted phospholene derivatives in good yield. Only trans substitution in relation to the P-Ph group was observed. Treatment of lithiated phospholene intermediates with 1,3-dihaloalkanes afforded annulated 2-phenyl-2phosphabicyclo[3.3.0]oct-3-ene derivatives. The annulation reactions occurred with high regio- and stereoselectivity and led to the exclusive formation of the exo-Ph-P substituted products. (C) 2004 Elsevier Ltd. All rights reserved.