Asymmetric hydrogenation of pyridinium salts with an iridium phosphole catalyst.
نویسندگان
چکیده
Iridium-catalyzed asymmetric hydrogenation of N-alkyl-2-alkylpyridinium salts provided 2-aryl-substituted piperidines with high levels of enantioselectivity. Simple benzyl and other alkyl groups successfully activated the challenging pyridine substrates toward hydrogenation. The use of the unusual chiral-phosphole-based MP(2) -SEGPHOS was the key to the success of this approach which provides a versatile and practical procedure for the synthesis of chiral piperidines.
منابع مشابه
A Mixed Ligand Approach for the Asymmetric Hydrogenation of 2Substituted Pyridinium Salts
Herein we describe a new methodology for the asymmetric hydrogenation (AH) of 2-substituted pyridinium salts. An iridium catalyst based on a mixture of a chiral monodentate phosphoramidite and an achiral phosphine was shown to hydrogenate N-benzyl-2-arylpyiridinium bromides to the corresponding N-benzyl-2-arylpiperidines with full conversion and good enantioselectivity. The mechanism of the rea...
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عنوان ژورنال:
- Angewandte Chemie
دوره 53 47 شماره
صفحات -
تاریخ انتشار 2014