Anomalous Hydroboration at a Four-Coordinate Ni(II) Diphenylvinylphosphine Complex: Geometric Impacts on Solution Equilibria
作者:Marissa L. Clapson、Brady J. H. Austen、Joseph A. Zurakowski、Marcus W. Drover
DOI:10.1021/acs.organomet.3c00442
日期:2024.1.22
This report examines a family of monophosphine-ligated nickel(II) dihalide compounds containing secondary coordination sphere borane groups. Interestingly, anomalous hydroboration of trans-[NiII(X)2(PPh2Vin)2] (Vin = vinyl) was witnessed upon treatment with HBCy2 (Cy = cyclohexyl), resulting in halide-directed Markovnikov hydroboration; these branched products were observed to be diamagnetic in solution
Synthesis and Reactivity of Ruthenium Arene Complexes Incorporating Novel Ph<sub>2</sub>PCH<sub>2</sub>CH<sub>2</sub>BR<sub>2</sub> Ligands. Easy Access to the Four-Membered Ruthenacycle [(<i>p</i>-cymene)RuCl(κ<sup>C,P</sup>-CH<sub>2</sub>CH<sub>2</sub>PPh<sub>2</sub>)]
The ambiphilic ligands Ph2PCH2CH2BR2 (1a,b: BR2 = BCy2 (a), 9-BBN (b)) were readily prepared by hydroboration of vinyldiphenylphosphine. Reaction of 1a,b with [(p-cymene)RuCl2](2) afforded the corresponding complexes [(p-cymene)RuCl2(Ph2PCH2CH2BR2)] (2a,b), in which the borane moiety remains pendant, as confirmed by an X-ray diffraction analysis of 2b. Reaction of 2a,b with AgBF4 in the presence of acetonitrile leads to the formation of the corresponding cationic complexes [(p-cymene)RuCl(Ph2PCH2CH2BR2)(CH3CN)][BF4] (3a,b) without alteration of the pendant borane moiety. In contrast, treatment of 2a,b with AgOAc induces CH2-B bond cleavage and affords the four-membered ruthenacycle [(p-cymene)RuCl(K-C,K-P-CH2CH2PPh2)] (4), characterized by X-ray diffraction. By reaction with chlorodicyclohexylborane, 4 gives back 2a via ring-opening sigma-bond metathesis, whereas 4 reacts with chlorodiethylalane via alkylation at ruthenium with retention of the four-membered metallacycle to afford the ethyl complex [(p-cymene)RuEt(K-C,K-P-CH2CH2PPh2)] (5).
β-Phosphinoethylboranes as Ambiphilic Ligands in Nickel−Methyl Complexes
作者:Andreas Fischbach、Patrick R. Bazinet、Rory Waterman、T. Don Tilley
DOI:10.1021/om7010886
日期:2008.3.24
studies of compound 1b revealed infinite helical chains of the molecules connected through P···B donor–acceptor interactions. The ability of these ambiphilicligands to concurrently act as donors and acceptors was highlighted by their reactions with (dmpe)NiMe2. The zwitterionic complexes (dmpe)NiMe(Ph2PCH2CH2BCy2Me) (2a) and (dmpe)NiMe(Ph2PCH2CH2[BBN]Me) (2b) were generated via the abstraction of one