Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
Angew Chem Int Ed Engl. 2018 Feb 19;57(8):2188-2193. doi: 10.1002/anie.201712624. Epub 2018 Jan 25.
The synthesis and characterization of a stable phosphaethynolatoborane, [B]OCP (1, [B]=N,N'-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-1,3,2-diazaboryl), is described. The increased triple bond character of the P-C bond in 1 relative to the free ion (PCO ) is probed in a series of reactivity studies. Compound 1 readily dimerises in donor solvents to afford a cyclic five-membered 6π-aromatic compound, cyclo-P {C[B]}O{CO[B]} (2), which decarbonylates on UV irradiation. By contrast the nickel-mediated dimerisation of 1 affords the isomeric diphosphacyclobutene [P(CO[B])] . When 1 is reacted with organolithium reagents such as MesLi (Mes=2,4,6-trimethylphenyl), the boryl moiety shifts and the formation of the lithoxy-boryl-phosphaalkene [LiOC[B]P(Mes)] was observed. The reactivity of this species towards electrophiles is also described.
稳定的膦炔基硼烷 [B]OCP（1，[B]=N,N'-双（2,6-二异丙基苯基）-2,3-二氢-1H-1,3,2-二氮杂硼基）的合成与表征。在一系列反应性研究中，探测了 1 中 P-C 键相对于游离离子（PCO）的叁键特征增加。化合物 1 在给体溶剂中容易二聚形成环状五元 6π-芳族化合物，环-P{C[B]}O{CO[B]}（2），其在紫外线照射下脱羰。相比之下，镍介导的 1 二聚化生成异构二膦环丁烯[P(CO[B])]。当 1 与有机锂试剂如 MesLi（Mes=2,4,6-三甲基苯基）反应时，硼基部分迁移，形成甲氧基硼基膦烯[LiOC[B]P（Mes）]。还描述了该物种对亲电试剂的反应性。
