Asymmetric Hydrogenation of Six-Membered Ring Heteroarenes

Asymmetric Hydrogenation of Five-Membered Ring Heteroarenes 

Enantioselective hydrogenation of pyrroles has also been conducted, and is somewhat more complex than that of indoles. These reactions were conducted with N-Boc-substituted pyrroles and a ruthenium-TRAP catalyst. The pyrroles can be mono-, di-, or tri-substituted. For example, the asymmetric reduction of 4,5-dimethylpyrrole-2-carboxylate gave the product from addition of hydrogen to the same face of both olefin units to form products containing three stereocenters in high enantioselectivity. These reactions occur by initial reduction of the less-substituted carbon-carbon double bond. 

Homogeneous Hydrogenation of Other Functional Groups (Written with Prof. Jing Zhao) 

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