Microwave-assisted rhodium-complex-catalyzed cascade decarbonylation and asymmetric Pauson-Khand-type cyclizations

摘要

Microwave-assisted Rh-diphosphane-complex-catalyzed dual catalysis is reported. This cooperative process provides [2+2+1] cycloadducts by sequential decarbonylation of aldehyde or formate and carbonylation of enynes within a short period of time. Various O-, N-, and C-tethered enynes were transformed into the corresponding products in good yields. The first enantio selective version of this microwave-accelerated cascade cyclization was realized. In the presence of chiral Rh-(S)-bisbenzodioxanPhos complex, the cyclopentenone products were achieved with ee values up to 90 %. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).