Bulletin of the Chemical Society of Japan p. 473 - 480 (1981)
Update date:2022-09-26
Topics:
Yamamoto, Gaku
Oki, Michinori
Stereodynamics of a variety of 9-(3,5-dimethylbenzyl)triptycene derivatives was studied.Atropisomerism about the bridgehead-to-methylene bond was realized in a triply peri-substituted derivative, 8,13-dichloro-1,4-dimethyl-9-(3,5-dimethylbenzyl)triptycene: the activation enthalpy for the ap--> +/-sc conversion was 26.4 kcal/mol.Barriers to rotation about the bridgehead-to-methylene bond in a variety of triply, doubly, and singly peri-substituted derivatives were obtained by DNMR method.DNMR behavior of the diastereotopic m-methyl groups in the benzyl moiety revealed the dual mechanisms of the methyl exchange process; rotation about the methylene-to-aryl bond by 180 deg without rotation about the bridgehead-to-methylene bond ("isolated rotation (IR)") and rotation about the methylene-to-aryl bond by 180 deg synchronous with rotation about the bridgehead-to-methylene bond by 120 deg ("gear motion (GM)").The GM process predominates in peri-unsubstituted derivatives, while the IR process predominates in triply peri-substituted ones.
View MoreContact:+86-838-5655598
Address:Guanghan Nanfeng Industrial Zone
Contact:86-25-84683399
Address:605, Phoenix Herui Plaza, No.389, South Taiping Road, Nanjing, China 210002
Jiangxi Dongbang Pharmaceutical Co., Ltd.
Contact:+86-795-4433603, 4433388
Address:Fengxin Industrial Park, Fengxin County, Jiangxi Province, P.R.C
Zhejiang Chemicals Import & Export Corporation
Contact:86-571-87043088
Address:No.37,Qingchun Road,Hangzhou,China
Huangshi Shennong Chemical Technology Co., Ltd
Contact:+86-714-3072290
Address:Eastern industrial park , Tieshan district , Huangshi city ,Hubei province , China
Doi:10.1039/P19810000672
(1981)Doi:10.1016/j.poly.2004.07.005
(2004)Doi:10.1246/bcsj.54.1132
(1981)Doi:10.1021/acs.jafc.9b03633
(2019)Doi:10.1021/jo00334a012
(1981)Doi:10.1016/j.tetasy.2009.05.014
(2009)