Tributyltin hydride (Tributylstannane), Tin hydrides

Organotin hydrides are very good radical reducing agents due to the relatively weak, nonionic bond between tin and hydrogen (Bu₃SnH 74 kcal/mol) that can cleave homolytically.

Tributyltin hydride

However, these compounds are plagued by their high toxicity and high fat solubility (lipophilicity). Therefore, with few exceptions, the use of tin hydrides should be avoided. The catalytic use of this reagents with a suitable second reducing agent, or the use of radical H-donors such as indium hydrides and silanes [especially tris(trimethylsilyl)silane] are possible alternatives.

Tin is characterized by a pronounced affinity for sulfur, which can be exploited in various reactions:

Barton-McCombie reaction

Barton decarboxylation

Additional interesting reactions that employ tin hydrides are dehalogenation and intramolecular radical cyclization.

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Recent Literature

An organotin hydride-catalyzed, silicon hydride-mediated method for effecting the conjugate reduction of α,β-unsaturated ketones was developed.
D. S. Hays, M. Scholl, G. C.Fu, J. Org. Chem., 1996, 61, 6751-6752.

A stannane, which is simple to prepare, was successfully used in standard radical reactions as replacement of Bu₃SnH and Ph₃SnH. The tin-containing byproducts are removed by mild hydrolysis and extraction with aqueous NaHCO₃. The performance of this new reagent was tested for reactions involving halides, selenides, Barton-McCombie deoxygenation and enyne cyclization.
D. L. J. Clive, J. Wang, J. Org. Chem., 2002, 67, 1192-1198.

D. L. J. Clive, J. Wang, J. Org. Chem., 2002, 67, 1192-1198.

D. L. J. Clive, J. Wang, J. Org. Chem., 2002, 67, 1192-1198.

D. L. J. Clive, J. Wang, J. Org. Chem., 2002, 67, 1192-1198.

The synthesis of indoles alkaloids has been achieved employing a Bartoli synthesis/heteroaryl radical approach. The introduction of various vinyl Grignard reagents seemed to have little effect on the indole synthesis. Thus, the Bartoli reaction represents a rapid route to a range of complex 7-bromo-substituted indoles. The reduction of 7-bromoindoles with tributyltin hydride under standard conditions gave indoles in nearly quantitative yields.
A. Dobbs, J. Org. Chem., 2001, 66, 638-641.