excellent enantiomeric excesses (up to> 99% ee) from the corresponding 1-and 4-
oxotetrahydrocarbazoles through asymmetric transfer hydrogenation by using the
commercially available Noyori–Ikariya ruthenium catalyst. The immediate use of the freshly
prepared catalyst and the use of a HCO 2 H–DABCO (11: 6) mixture as the hydrogen source
are crucial for achieving high activity and enantioselectivity. In this way, a …