Insertion of CO2 and COS into Bi–C Bonds: Reactivity of a Bismuth NCN Pincer Complex of an Oxyaryl Dianionic Ligand, [2,6-(Me2NCH2)2C6H3]Bi(C6H2tBu2O)

The reactivity of the unusual oxyaryl
dianionic ligand, (C6H2tBu2-3,5-O-4)2–, in the Bi3+ NCN pincer complex Ar′Bi­(C6H2tBu2-3,5-O-4), 1, [Ar′ = 2,6-(Me2NCH2)2C6H3] has been explored with small molecule
substrates and electrophiles. The first insertion reactions of CO2 and COS into Bi–C bonds are observed with this oxyaryl
dianionic ligand complex. These reactions generate new dianions that
have quinoidal character similar to the oxyaryl dianionic ligand in 1. The oxyarylcarboxy and oxyarylthiocarboxy dianionic ligands
were identified by X-ray crystallography in Ar′Bi­[O2C­(C6H2tBu2-3-5-O-4)-κ2O,O′], 2, and Ar′Bi­[OSC­(C6H2tBu2-3-5-O-4)-κ2O,S], 3, respectively. Silyl halides and pseudohalides,
R3SiX (X = Cl, CN, N3; R = Me, Ph), react with 1 by attaching X to bismuth and R3Si to the oxyaryl
oxygen to form Ar′Bi­(X)­(C6H2tBu2-3,5-OSiR3-4) complexes,
a formal addition across five bonds. These react with additional R3SiX to generate Ar′BiX2 complexes and R3SiOC6H3tBu2-2,6. The reaction of 1 with I2 forms Ar′BiI2 and the coupled quinone, 3,3′,5,5′-tetra-tert-butyl-4,4′-diphenoquinone, by oxidative coupling.

针对异常氧芳基双负电荷配体（C6H2tBu2-3,5-O-4）2–在Bi3+ NCN 锥形配位复合物Ar′Bi(C6H2tBu2-3,5-O-4)，1中[Ar′ = 2,6-(Me2NCH2)2C6H3]的反应活性进行了研究，该研究采用了小分子底物和亲电试剂。利用该氧芳基双负电荷配体复合物，首次观察到CO2和COS分子插入Bi-C键的反应。这些反应产生了新的双负离子，其共轭结构性质与1中的氧芳基双负电荷配体相似。通过X射线晶体学在Ar′Bi[O2C(C6H2tBu2-3-5-O-4)-κ2O,O′]，2和Ar′Bi[OSC(C6H2tBu2-3-5-O-4)-κ2O,S]，3中分别鉴定了氧芳基羧基和氧芳基硫代羧基双负电荷配体。三卤硅烷和假卤化物R3SiX（X = Cl, CN, N3；R = Me, Ph）与1反应，通过将X连接到铋原子并将R3Si连接到氧芳基氧原子，形成了Ar′Bi(X)(C6H2tBu2-3,5-OSiR3-4)复合物，这是一种跨越五个键的正式加成反应。这些复合物与额外的R3SiX反应，生成了Ar′BiX2复合物和R3SiOC6H3tBu2-2,6。1与I2的反应形成了Ar′BiI2以及通过氧化偶联生成的偶联醌，即3,3′,5,5′-四叔丁基-4,4′-二苯醌。