Asymmetric hydroamination.

The direct addition of amine N-H bonds across an unsaturated carbon-carbon linkage gives fast and highly atom-economical access to amines. This review provides an overview of the most effective stereoselective methods using various catalyst systems based on alkali, alkaline earth, and transition metals, as well as enzymatic and organocatalytic approaches. Except for a few sporadic examples in the last century, this field has evolved primarily over the last decade.

The mechanism of hydroaminoalkylation catalyzed by group 5 metal binaphtholate complexes.

The intermolecular hydroaminoalkylation of unactivated alkenes and vinyl arenes with secondary amines occurs readily in the presence of tantalum and niobium binaphtholate catalysts with high regio- and enantioselectivity (up to 98% ee). Mechanistic studies have been conducted in order to determine the kinetic order of the reaction in all reagents and elucidate the rate- and stereodetermining steps. The effects of substrate steric and electronic properties on the overall reaction rate have been evaluated.

Kinetic resolution of aminoalkenes by asymmetric hydroamination: a mechanistic study.

The kinetic resolution of chiral aminoalkenes by hydroamination-cyclization was studied by using 3,3'-bis(triarylsilyl)-substituted binaphtholate rare-earth-metal complexes. The resolution of 1-arylaminopentenes proceeds with high efficiency and high trans-diastereoselectivity, whereas the resolution process of 1-alkylaminopentenes suffers from decreasing resolution efficiency with increasing steric demand of the aliphatic substituent. Kinetic studies of the matching and mismatching substrate-catalyst pair by using enantiopure substrates and either the (R)- or (S)-binaphtholate catalysts revealed that the difference in resolution efficiency stems from a shift of the Curtin-Hammett pre-equilibrium.