摘要:
IntroductionAsymmetric induction is efficiently achieved by solid state reaction of a chiral salt crystal formed from a carboxylic acid and an amine, one of which is a chiral compound acting as an ionic chiral handle.1–5It is known that 2,4,6triisopropyl4′carboxybenzophenone undergoes a Norrish type II photoreaction to give the cyclobutenol in the solid state and in the solution phase.6,7Reaction in salt crystals formed from the 4′carboxylic acid derivative with chiral amines, as an ionic chiral handle, produces the chiral cyclobutenol.8Furthermore, single crystaltosingle crystal enantioselective photocyclization has already been achieved as the salt crystal withLprolinol, but the problem remains in that the optical yield is low, only 30% ee.9Herein we report the enantiospecificsingle crystaltosingle crystal reaction of 2,5diisopropyl4′carboxybenzophenone1, in the salt crystals1·(S)2and1·(R)2, with (S) and (R)phenylethylamine2(Scheme 1). The reaction process was traced by Xray crystallographic analysis.
ISSN:1466-8033
DOI:10.1039/b103517g
出版商:RSC
年代:2001
数据来源: RSC