The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 19, 2009
Filed:
Mar. 05, 2008
Tsuneo Imamoto, Chiba, JP;
Kazuhiro Yoshida, Chiba, JP;
Youichi Saitoh, Chiba, JP;
Aya Koide, Chiba, JP;
Tsuneo Imamoto, Chiba, JP;
Kazuhiro Yoshida, Chiba, JP;
Youichi Saitoh, Chiba, JP;
Aya Koide, Chiba, JP;
Nippon Chemical Industrial Co., Ltd., Tokyo, JP;
National University Corporation Chiba University, Chiba-shi, JP;
Abstract
An optically-active bis(alkynylphosphino)ethane-borane derivative represented by formula (1): The derivative (1) is prepared by bromination of, e.g., an (S)-t-butylmethylphosphine-borane, reaction with an alkynyl lithium, deprotonation, followed by oxidative coupling. Deprotection of the derivative (1) by deboranation gives an optically-active bis(alkynylphosphino)ethane derivative useful as a ligand providing an asymmetric catalyst for catalytic asymmetric synthesis. The asymmetric catalyst having the ligand exhibits high selectivity and catalyst activity.