Issue 5, 2016

Spontaneous dehydrocoupling in peri-substituted phosphine–borane adducts


Bis(borane) adducts Acenap(PiPr2·BH3)(PRH·BH3) (Acenap = acenaphthene-5,6-diyl; 4a, R = Ph; 4b, R = ferrocenyl, Fc; 4c, R = H) were synthesised by the reaction of excess H3B·SMe2 with either phosphino-phosphonium salts [Acenap(PiPr2)(PR)]+Cl (1a, R = Ph; 1b, R = Fc), or bis(phosphine) Acenap(PiPr2)(PH2) (3). Bis(borane) adducts 4a–c were found to undergo dihydrogen elimination at room temperature, this spontaneous catalyst-free phosphine-borane dehydrocoupling yields BH2 bridged species Acenap(PiPr2)(μ-BH2)(PR·BH3) (5a, R = Ph; 5b, R = Fc; 5c, R = H). Thermolysis of 5c results in loss of the terminal borane moiety to afford Acenap(PiPr2)(μ-BH2)(PH) (14). Single crystal X-ray structures of 3, 4b and 5a–c are reported.

Graphical abstract: Spontaneous dehydrocoupling in peri-substituted phosphine–borane adducts

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Article information

Article type
03 Jul 2015
21 Aug 2015
First published
21 Aug 2015
This article is Open Access
Creative Commons BY license

Dalton Trans., 2016,45, 1976-1986

Author version available

Spontaneous dehydrocoupling in peri-substituted phosphine–borane adducts

L. J. Taylor, B. A. Surgenor, P. Wawrzyniak, M. J. Ray, D. B. Cordes, A. M. Z. Slawin and P. Kilian, Dalton Trans., 2016, 45, 1976 DOI: 10.1039/C5DT02539G

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