Journal of Organic Chemistry p. 162 - 167 (1986)
Update date:2022-08-05
Topics:
Brown, Charles A.
Desai, Manoj C.
Jadhav, Prabhakav K.
Iodine-induced rearrangement of the "ate" complex derived from diisopinocampheylalkylborane and various lithium acetylides furnishes optically active disubstituted alkynes with an enantiomeric excess comparable to that of the diisopinocampheylborane used in the initial asymmetric hydroboration.In the present investigation sec-butyldiisopinocampheylborane, prepared by asymmetric hydroboration of cis-2-butene with chiral diisopinocampheylborane of high enantiomeric excess, is used to yield sec-butyl-substituted alkynes in excellent (>=95percent) enantiomeric excess.Despite the statistical disadvantage of a 1:2 ratio of sec-butyl:isopinocampheyl groups, the desired alkyne is formed in 58percent yield by GLPC, compared to 38percent for the product derived from the migration of the isopinocampheyl group, thus suggesting low migratory aptitude for the latter.The iodine-induced rearrangement is highly stereospecific in nature and proceeds with complete retention of configuration at the migrating terminus.The method is capable of producing both enantiomers.
View MoreDaqing New Century Fine Chemical Co., Ltd.(expird)
Contact:010-57126694
Address:No.39, jinxing cun, honggang district
Engineering Research Center of Pesticide, Heilongjiang Province
Contact:+86-451-86609001
Address:No.74 of Xuefu Road, Nangang District,
RongCheng K&S Chemical Co.,Ltd
Contact:0631-7336369
Address:rongcheng ,shandong province china
Huangshi Meifeng Chemical Co.,ltd.
Contact:+86-714-6516706
Address:1941-4-3#,Hubin Avenue,Huangshi,Hubei,China
Hangzhou Hysen Pharma co.,Ltd.
website:http://www.hysenpharma.cn/
Contact:0086-571-88298791
Address:#701,Gudun Road Hangzhou
Doi:10.1016/S0040-4039(00)96047-7
(1987)Doi:10.1016/j.tet.2007.05.049
(2007)Doi:10.1080/07328300600735181
(2006)Doi:10.1016/j.tetlet.2006.04.160
(2006)Doi:10.1016/S0040-4039(01)80027-7
(1984)Doi:10.1021/jm0602559
(2006)