Regioselective Hydroformylation of Allylic Alcohols

Highly regioselective osmium-catalyzed hydroformylation.

The first highly regioselective and general osmium-catalyzed hydroformylation of olefins to aldehydes is reported. The combination of Os3(CO)12 and imidazoyl-substituted phosphine ligands allows n-selective (up to 99%) hydroformylation of bulk aliphatic as well as functional alkenes in good yields (64-87%).

Regioselective Rhodium-Catalyzed Allylic Amination

Catalytic enantioselective bromoamination of allylic alcohols.

An enantioselective bromoamination of allylic alcohols has been developed for the first time using a newly designed cinchona-derived thiourea as the catalyst and N,N-dibromo-4-nitrobenzenesulfonamide as a bromine and amine source.

Catalytic enantioselective dibromination of allylic alcohols.

A new dibromination reaction involving the combination of dibromomalonate as the bromonium source and a titanium bromide species as the bromide source has been developed. Enantioselective catalysis has been achieved through apparent ligand acceleration by a tartaric acid-derived diol.

Regioselective and diastereoselective allylic amination using chlorosulfonyl isocyanate. A novel asymmetric synthesis of unsaturated aromatic 1,2-amino alcohols.

The diastereoselective synthesis of unsaturated aromatic 1,2-amino alcohols can be achieved on an epimeric mixture of optically active allylic ethers having a hydroxyl group attached to an allylic chiral center to the pi-system using chlorosulfonyl isocyanate. These reactions produced the unsaturated anti-1,2-amino alcohols either exclusively or predominantly only for aromatic derivatives. The ...