Organosilicon compounds act as a nucleophile upon activation by an appropriate base and behave in a manner similar to main-group organometallic reagents. In the last decades, structurally divergent organosilicon reagents are available and have become more employed for synthetic transformation with the aid of transition-metal complexes, because organosilicon compounds are in general superior to other organometallic compounds in view of stability, solubility, nontoxicity, and easy-handling. Particularly, cross-coupling of organosilicon reagents with organic halides or pseudohalides has been considered to be a useful tool for constructing the carbon frameworks of various target molecules such as pharmaceuticals and π-conjugated functional materials. Perfluoroalkylsilicon compounds such as CF3SiEt3 have found use as reagents for the metal-catalyzed introduction of perfluoroalkyl groups into many substrates. In addition, functionalized organosilicon reagents are readily accessible by catalytic approach starting with appropriate hydrocarbons such as alkenes, alkynes, alkanes, and arenes. This article reviews recent advances in transition-metal-catalyzed transformations of organosilicon reagents according to the type of synthetic transformation and metal catalyst.

Whereas aryl(trialkyl)silanes are considered to be ideal organometallic reagents for cross-coupling reactions owing to their stability, low toxicity, solubility, and easy accessibility, they are generally inert under typical cross-coupling conditions. Disclosed herein is a palladium/copper catalytic system that enables the cross-coupling of trimethyl, triethyl, tert-butyldimethyl, and triisopropyl aryl silanes with aryl bromides. This process is applicable to the sequential C-H and C-Si bond arylation of thiophenes and the synthesis of poly(thiophene-fluorene)s.

Silylation of aryl bromides with disilanes of type {[2-(PGOCH2)C6H4]Me2Si}2 (PG: protecting group) successfully takes place in the presence of a Pd/Ruphos or Davephos/CuI catalytic system to afford HOMSi reagents containing various functional groups in good yields. BisHOMSi reagents were also prepared directly from the corresponding arylene dibromides.

Carbon–nitrogen bond-forming cross-coupling reaction of haloarenes with N-trimethylsilyl (TMS)-substituted secondary and primary arylamines proceeded with the aid of a palladium catalyst and a fluoride activator. Various TMS-N(aryl)2, TMS-NH(aryl), and TMS-N(alkyl)2 reacted to give the corresponding coupled products in high yields. Multi-TMS-amine nucleophiles such as N,N-(TMS)2-aniline and N,N′-Ph2-N,N′-(TMS)2-p-phenylenediamine also participated in this C–N coupling to give multiply C–N coupled products in high yields. The novel C–N cross-coupling reaction was successfully applied to C–N bond-forming polymerization. Relative rates of the cross-coupling of p-bromotoluene with N-TMS-substituted primary and secondary amines showed that N-TMS-diphenylamine reacted faster than N-TMS-N-methylaniline or N-TMS-aniline, and N-TMS-morpholine was the least reactive, indicating that the low basicity of the nitrogen nucleophile is the key for the smooth coupling.

The silicon-based cross-coupling reaction has attracted much attention over recent decades because there are many advantages in using organosilicon compounds. However, the use of reagents with a triorganosilyl group as a key function remains to be established. This account summarizes our recent progress in cross-coupling chemistry with such silyl reagents.