ABSTRACT A transition metal-free, direct one-potdominoallylation reaction of 2-pyridinyl Grignard reagents with polysubstituted allyl chlorides for the regioselective synthesis of pyridinyl-substituted 1,5-diene derivatives has been disclosed. The reaction presumably proceeded through the coupling of polysubstituted allyl chloride to 2-PyMgX, which was in situ generated from 2-bromopyridine with
Preference for β-H elimination in the termination of the Ni-promoted carbonylative cycloaddition of 2-haloethylidene-cycloalkanes and alkynes
作者:Fabiola Vilaseca、Lluı́s Pagès、Juan Manuel Villar、Amadeu Llebaria、Antonio Delgado、Josep Maria Moretó
DOI:10.1016/s0022-328x(97)00390-2
日期:1998.1
mutual conformation of the two rings in the intermediates favouring either elimination through enol formation or synβ-elimination. In this last case, the terminating step can proceed in two different modes, namely, intraannularly or interannularly. While for the acetylenic ester, the product from interannular elimination is exclusive or predominant regardless of the ring size of the starting halide,