Allyliccarbonates were more active than the corresponding allylic acetates in carbonylallylationusingPdCl2(PhCN)2-SnCl2, and the carbonylallylation by (E)-crotyl carbonate at 10 °C exhibited opposite diastereo-selectivity (anti-selectivity) to that by (E)-crotyl acetate at 60 ° C.
The performance of tert-butanesulfinamides as nitrogen nucleophiles in Pd(0)-catalyzed allylic substitution reactions has been investigated. Metalated N-alkyl and N-acetyl sulfinamides have been identified as suitable partners for the reaction with π-allyl–palladium complexes. The cross-coupling of N-acetyl tert-butanesulfinamide with 2- or 3-substituted linear allylic carbonates is achieved in the
Palladium-Catalyzed Asymmetric Allylic Alkylation of Ketone Enolates
作者:Barry M. Trost、Gretchen M. Schroeder
DOI:10.1002/chem.200400666
日期:2005.1
Palladium-catalyzed asymmetric allylic alkylation of nonstabilized ketone enolates to generate quaternary centers has been achieved in excellent yield and enantioselectivity. Optimized conditions consist of performing the reaction in the presence of two equivalents of LDA as base, one equivalent of trimethytin chloride as a Lewis acid, 1,2-dimethoxyethane as the solvent, and a catalytic amount of a
A“Chiral Aldehyde” Equivalent as a Building Block Towards Biologically Active Targets
作者:Barry M. Trost、Matthew L. Crawley
DOI:10.1002/chem.200305634
日期:2004.5.3
by the Bayer corporation. These studies further inspired work that culminated in the total synthesis of (+)-brefeldin A, a natural product with a range of significant biological properties. All of the stereochemistry in this target molecule was derived from two palladium-catalyzedasymmetricallylicalkylation reactions. The trans-alkenes were synthesized by a Julia olefination and a ruthenium-catalyzed
A highly regioselective palladium-catalyzedallylic alkylation of fluorobis(phenylsulfonyl)methane has been studied. Using different allylic carbonates, a variety of terminal mono-fluoromethylated compounds were achieved in 85–99% yields with high regioselectivities.