Continuous-flow catalytic asymmetric hydrogenations: Reaction optimization using FTIR inline analysis

Abstract

The asymmetric organocatalytic hydrogenation of benzoxazines, quinolines, quinoxalines and 3H-indoles in continuous-flow microreactors has been developed. Reaction monitoring was achieved by using an inline ReactIR flow cell, which allows fast and convenient optimization of reaction parameters. The reductions proceeded well, and the desired products were isolated in high yields and with excellent enantioselectivities.

Keywords

• asymmetric reduction
• binolphosphoric acid
• Brønsted acid
• Hantzsch dihydropyridine
• IR spectroscopy
• real-time analysis