Reversible Cyclometalation of Silyl Ligands. First X-ray Structure of an Iridium(I) Silyl That Is Not Stabilized by Chelation
Reversible Cyclometalation of Silyl Ligands. First X-ray Structure of an Iridium(I) Silyl That Is Not Stabilized by Chelation
复制标题
甲硅烷基配体的可逆环金属化。
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
D. Milstein
中科院分区：
文献类型：
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作者：
M. Aizenberg;D. Milstein
iridasilaclac fac-（PMe 3）3 Ir（o-C6 H4 SiMe 2）（H）（1）是由Ir（PMe 3）4Cl和PhMe 2SiLi在室温下生成的瞬态（PMe 3）3 Ir（SiMe 2 Ph）（7）的邻位金属化反应产生的。配合物1也可以由fac-（PMe 3）3 Ir（CH 3）（H）（SiMe 2 Ph）（6）获得，其在加热时还原消除甲烷。1及其类似物fac-（PMe 3）3 Ir（o-C6 H4 SiPh 2）（H）（2）在80 °C下与氢气反应，得到二亚甲基硅基铱（III）配合物fac-（PMe 3）3 Ir（SiR 2 Ph）（H）2（3，R = Me; 4，R = Ph）。1与氘的反应表明，iridasilaclate的初始开环发生，然后是D-D氧化加成为7。1与CO的反应使我们能够捕获铱（I）物种，并提供了Ir（PMe 3）2（CO）2（SiMe 2 Ph）（5）的合成路线。通过光谱和X射线晶体学鉴定了配合物5，它是由3和CO独立合成的。所提出的化学反应表明，硅基配体的金属化可以是一个容易的可逆过程，在温和的条件下发生。
The iridasilacycle fac-(PMe3)3Ir(o-C6H4SiMe2)(H) (1) results from the ortho metalation of the transient (PMe3)3Ir(SiMe2Ph) (7), generated from Ir(PMe3)4Cl and PhMe2SiLi at ambient temperature. Complex 1 can also be obtained from fac-(PMe3)3Ir(CH3)(H)(SiMe2Ph) (6), which, when heated, reductively eliminates methane. 1 and its analog fac-(PMe3)3Ir(o-C6H4SiPh2)(H) (2), react with hydrogen at 80 °C to yield the dihydridosilyliridium(III) complexes fac-(PMe3)3Ir(SiR2Ph)(H)2 (3, R = Me; 4, R = Ph). The reaction of 1 with deuterium demonstrates that initial opening of the iridasilacycle takes place, followed by D−D oxidative addition to 7. The reaction of 1 with CO allows us to trap the iridium(I) species and provides a synthetic route to Ir(PMe3)2(CO)2(SiMe2Ph) (5). Complex 5 was identified by spectroscopy and by X-ray crystallography and was synthesized independently from 3 and CO. The chemistry presented shows that metalation of silyl ligands can be a facile reversible process that takes place under mild cond...