title: Spontaneous dehydrocoupling in peri-substituted phosphine-borane adducts.
abstract: 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.
authors: School of Chemistry, EastCHEM, University of St Andrews, St Andrews, Fife, KY16 9ST, UK. pk7@st-andrews.ac.uk.
authors: Laurence J
authors: LJ
authors: Taylor
authors: Brian A
authors: BA
authors: Surgenor
authors: Piotr
authors: P
authors: Wawrzyniak
authors: Matthew J
authors: MJ
authors: Ray
authors: David B
authors: DB
authors: Cordes
authors: Alexandra M Z
authors: AM
authors: Slawin
authors: Petr
authors: P
authors: Kilian