周环取代膦-硼烷加合物中的自发脱氢偶联反应。

Spontaneous dehydrocoupling in peri-substituted phosphine-borane adducts.

作者信息

Taylor Laurence J, Surgenor Brian A, Wawrzyniak Piotr, Ray Matthew J, Cordes David B, Slawin Alexandra M Z, Kilian Petr

机构信息

School of Chemistry, EastCHEM, University of St Andrews, St Andrews, Fife, KY16 9ST, UK.

出版信息

Dalton Trans. 2016 Feb 7;45(5):1976-86. doi: 10.1039/c5dt02539g. Epub 2015 Aug 28.

DOI:10.1039/c5dt02539g

PMID:26314761

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.

摘要

通过使过量的H₃B·SMe₂与膦基鏻盐[Acenap(PiPr₂)(PR)]⁺Cl⁻（1a，R = Ph；1b，R = 二茂铁基，Fc）或双膦Acenap(PiPr₂)(PH₂)（3）反应，合成了双（硼烷）加合物Acenap(PiPr₂·BH₃)(PRH·BH₃)（Acenap = 苊-5,6-二亚基；4a，R = Ph；4b，R = 二茂铁基，Fc；4c，R = H）。发现双（硼烷）加合物4a - c在室温下会发生二氢消除反应，这种无催化剂的自发膦 - 硼烷脱氢偶联反应生成了由BH₂桥连的物种Acenap(PiPr₂)(μ - BH₂)(PR·BH₃)（5a，R = Ph；5b，R = Fc；5c，R = H）。5c的热解导致末端硼烷部分的损失，得到Acenap(PiPr₂)(μ - BH₂)(PH)（14）。报道了3、4b和5a - c的单晶X射线结构。