Enzymatic asymmetric synthesis of the silodosin amine intermediate
摘要:
Various enantiocomplementary omega-transaminases (omega TAs) were investigated in kinetic resolution and asymmetric reductive amination reactions to prepare silodosin amine. Whilst the enzymatic kinetic resolution gave moderate to good results with respect to the yield and enantioselectivity, the asymmetric reductive amination proved to be superior. The best results were obtained with the omega TA originating from (R)-Arthrobacter sp. which afforded the desired bioactive (R)-enantiomer in enantiomerically pure form (ee >97%) at excellent conversion (cony. >97%) under mild and benign reaction conditions. (C) 2013 Elsevier Ltd. All rights reserved.
The present invention relates to a process for preparing silodosin with high optical purity up to 99.9% enantiomeric excess (e.e.) or above. The process makes use of a method step, in which the enantiomers contained in a racemic mixture of a compound represented by the general formula V: wherein * denotes the asymmetric center, R
1
is a protecting group, and R
2
is cyano or carbamoyl, are separated.
most efficient methods for amine synthesis. Herein we report a practical homogeneous DRA procedure utilizing iridium catalysis. Applying simple, readily available and inexpensive PPh3 and alike ligands along with iridium at a low loading, aldehydes and ketones reductively coupled with primary and secondary amines to efficiently form structurally and functionally diverse amine products, including a set