Asymmetric hydrogenation of all-carbon tetrasubstituted α-acylpyrazole-β-alkyl cycloalkenes

Abstract

A general method for Ir-catalyzed asymmetric hydrogenation of tetrasubstituted α-acylpyrazole-β-alkyl cycloalkenes has been developed, furnishing 1,2-cis substituted carbo- or heterocycles with high yields and excellent enantioselectivities.

Recent advances in the metal-catalyzed asymmetric alkene hydrogenation of cyclic conjugated carbonyl compounds

“…Song & Qin 31 developed an Ir/spiro phosphoramidite L19 complex catalyzed asymmetric hydrogenation of tetrasubstituted α,β-unsaturated cyclic acylpyrazoles S9 bearing a variety of β-alkyl substituents to give 1,2- cis carbo- or heterocycles P9 in high stereopurity (Scheme 6b, up to 99% ee). It was proposed that the acylpyrazole motif serves as a key directing group by coordinating to the active Ir-complex.…”