Highly enantioselective hydrogenation of aromatic-heteroaromatic ketones.
Asymmetric hydrogenation of ketone 1 using trans-RuCl(2)[(R)-xylbinap][(R)-daipen] (3) as a catalyst afforded secondary alcohol 2 quantitatively and in 99.4% ee. Further exploration of the effect of the thiazole ring substitution revealed that the catalyst was highly effective for the enantioselective hydrogenation of 5-benzoyl thiazoles, which afforded corresponding alcohols in 92-99% ee. The same protocol was applicable to a variety of aromatic-heteroaromatic ketones to generate secondary alcohols in excellent enantioselectivities. [reaction: see text]
Chen
Cheng-yi
CY
Department of Process Research, Merck & Co., Inc., P.O. Box 2000, Rahway, NJ 07065-0900, USA. cheng-chen@merck.com
Reamer
Robert A
RA
Chilenski
Jennifer R
JR
McWilliams
J Christopher
JC
McWilliams
Chris J
CJ