Dibutylstannyl dichloride

Water was supposed to limit rearrangements between allenyltributylstannane and dibutylstannyl dichloride while these reagents were allowed to react with aldehydes. Nevertheless, complete a-allenic stereoconvergence was not observed. Homopropargylic alcohols could be obtained as well, especially with formaldehyde or a,p-unsaturated aldehydes (Boaretto et al., 1985b). 

To a dry nitrogen-filled, 10-mL, round-bottomed flask containing (Z)-crotyltributylstannane (0.345 g, 1 mmol), carbonyl substrate (0.195 g, 1 mmol) in THF (1 mL) are added dibutylstannyl dichloride (0.303 g, 1 mmol) and HMPA (0.180 g, 1 mmol) at rt. After stirring at 60 C for 3 h, the reaction mixture is cooled to 0 °C. To this mixture is added tosyl isocyanate (0.197 g, 1 mmol) and stirred for 1 h. IR absorption band of NCO (2200 cm-1) disappears, which indicates the formation of stannylcarbamate adduct. The mixture is warmed to 60 C and stirred for 0.5 h. The reaction is quenched by MeOH (0.5 mL), and the residue is chromatographed on siliea gel column. By-products such as organotin compounds are removed by eluting with hexane. Subsequent elusion with EtOAc gives the desired product (62%). Further purifieation is performed by recrystallization. ... 

To a dry nitrogen-filled, 10-mL, round-bottomed flask containing crotyltributylstannane (0.345 g, 1 mmol) in THF (1 mL) is added dibutylstannyl dichloride (0.303 g, 1 mmol) at rt. 

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See also in sourсe #XX -- [ ]

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