Palladium(0)-catalyzed cyclization-carbonylation of 2,7-octadienyl acetate and homologues
摘要:
The palladium(0)-catalyzed carbonylations, in acetic acid as a necessary solvent, of 2,7-octadienyl acetate and homologues via pi-allylpalladium species were preceded by their intramolecular oelfin insertion to form mixtures of cis/trans-2-vinylcyclopentylacetyl- and cis/trans-cyclohexylacetylpalladium intermediates, which undergo further the intramolecular (5-exo) Heck reaction to give bicyclo-[3.3.0] and [4.3.0] skeletons, respectively, except for one case affording trans-2-vinylcyclopentylacetic acid as a major product.
Enantio- and Diastereoselective Spiroketalization Catalyzed by Chiral Iridium Complex
作者:James Y. Hamilton、Simon L. Rössler、Erick M. Carreira
DOI:10.1021/jacs.7b02856
日期:2017.6.21
complex-catalyzed enantio- and diastereoselective formation of substituted spiroketals from racemic, allylic carbonates is reported, which enables the installation of multiple stereogenic centers in a single operation. The protocol was effective for the preparation of a collection of spiroketals of various ring sizes and substituents, including heteroatoms with high enantio- and diastereoselectivity. Furthermore