Tributyltin Hydride

Synthesis

In a 1000ml reaction flask, add 300g (0.5mol) of tributyltin hydride oxide and 100g of hydrogen-containing polysiloxane or hydrogen-containing polysiloxane waste (1% hydrogen content) while stirring. The reaction system is slowly heated (generally not exceeding 20℃; for large quantities, cooling should be considered). After about 1 hour, the heating is stopped, and stirring continues for 30 minutes. The fraction at 105~107℃/0.8kPa is collected by vacuum distillation to obtain a colorless liquid, namely tributyltin hydride.

Uses

Chemical Properties

clear colourless liquid

Uses

A widely used radical reagent used in reductive cleavage,1 radical dehalogenation, and intramolecular radical cyclization.2

Uses

Tributyltin hydride is used to effect carbon—carbon bond formation with the displacement of halide from a suitably oriented haloalkyl group.

Uses

Tributyltin hydride the most commonly used tin hydride，it is less toxic than the more volatile trierhyl and trimethyl analogues, and it is therefore the most widely used organostannane.
Tributyltin hydride, the reagent of choice for generating alkyl radical, is also widely used in aryl radical cyclization. Other reagents developed for this purpose include samarium diiodide, palladium reagents organosilanes as well as manganese triacetate and transition metals for carbocyclization.

Application

Has been reviewed. Catalyzes the Si-H reduction of α,β-unsaturated ketones. Useful in the reductive amination of ketones and aldehydes to form 3° amines.

Hazard

Moderately toxic by inhalation.

reaction suitability

reagent type: reductant

Safety Profile

Moderately toxic by inhalation. When heated to decomposition it emits acrid smoke and irritating fumes. See also TIN COMPOUNDS.

Purification Methods

Dissolve it in Et2O, add quinol (500mg for 300mL, to stabilize it), dry over Na2SO4, filter, evaporate and distil it under dry N2. It is a clear liquid if dry and decomposes very slowly. In the presence of H2O, traces of tributyl tin hydroxide are formed in a few days. Store it in sealed glass ampoules in small aliquots. It is estimated by reaction with aqueous NaOH when H2 is liberated. CARE: stored samples may be under pressure due to liberated H2. [Van Der Kerk et al. J Appl Chem 7 366 1937, Ono et al. Tetrahedron 41 4013 1985, Neuman Synthesis 665 1987, Curran Synthesis 417 1988, Beilstein 4 IV 4312.]