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ホスフィニデン架橋型Mo-Re錯体の効率的合成と多サイト反応性の研究求核性と求電子性を兼ね備えたプラットフォーム
Efficient Synthesis and Multisite Reactivity of a Phosphinidene-Bridged Mo-Re Complex. A Platform Combining Nucleophilic and Electrophilic Features.
PMID: 32628845 DOI: 10.1021/acs.inorgchem.0c01554.
抄録
MoCp(PClR*)(CO)とMoReCp(μ-PR*)(CO)を中間種(R* = 2,4,6-CHBu)として用いた3段階の反応により、-[MoCp(PHR*)(CO)]からヘテロ金属錯体[MoReCp(μ-PR*)(CO)]を60%の収率で合成した。PR*配位子は、一方の原子(Mo)との二重結合ともう一方の原子(Re)との二元的な単結合を含む、ジメタル中心との新しい不斉相互作用を示した。化合物はC-H結合の切断を含む熱異性化を受けて水素化物[MoReCp(μ-H){μ-P(CHCMe)CHBu}(CO)]を生成し、Iと反応して[MoReCpI(μ-PR*)(CO)]を生成し、対称的なホスフィニデン橋を表示します。293 Kでのプロピオレートメチルとの反応は、アルキンの[2 + 2]環化付加と脱カルボニル化を経て、ホスファプロペニリデン架橋錯体[MoReCp{μ-κ.η-PR*CHC(COMe)}(CO)を主生成物とし、273Kで過剰のCN(4-CHOMe)と反応させると、イソシアニドの正式な[2 + 1]環化付加反応が進行し、Re部位でさらにイソシアニドが付加されて錯体[MoReCp{μ-η.κ-PR*CN(4-CHOMe)}(CO){CN(4-CHOMe)}]という新しい架橋配位モードでのアザホスファレン配位子が得られました。
The heterometallic complex [MoReCp(μ-PR*)(CO)] () was prepared in 60% overall yield from -[MoCp(PHR*)(CO)] via a three-step procedure involving complexes -[MoCp(PClR*)(CO)] and [MoReCp(μ-PR*)(CO)] as intermediate species (R* = 2,4,6-CHBu). The PR* ligand in displays a novel asymmetric interaction with the dimetal center, involving a double bond with one atom (Mo) and a dative single bond with the other one (Re). Compound underwent thermal isomerization involving a C-H bond cleavage to yield the hydride [MoReCp(μ-H){μ-P(CHCMe)CHBu}(CO)] and reacted with I to give [MoReCpI(μ-PR*)(CO)], which displays a symmetrical phosphinidene bridge. Its reaction with methyl propiolate at 293 K proceeded with [2 + 2] cycloaddition of the alkyne and decarbonylation to yield the phosphapropenylidene-bridged complex [MoReCp{μ-κ:η-PR*CHC(COMe)}(CO)] as the major product, whereas its reaction with excess CN(4-CHOMe) at 273 K proceeded with formal [2 + 1] cycloaddition of the isocyanide and further isocyanide addition at the Re site to yield the complex [MoReCp{μ-η:κ-PR*CN(4-CHOMe)}(CO){CN(4-CHOMe)}], which displays an azaphosphaallene ligand in a novel bridging coordination mode.