THE SILYL-CUPRATION AND STANNYL-CUPRATION OF ALLENES

Article abstract of DOI:10.1016/0040-4020(89)80069-9

The stoichiometric silyl-cupration of allene 7, followed directly by treating the intermediate cuprate with a proton, with a range of carbon electrophiles, and with chlorine gives the vinylsilanes 8-13.Alternatively, when iodine is the electrophile, the product is the vinyl iodide 16.This can then be metallated and treated with a proton or a range of carbon electrophiles to give the allylsilanes 18-21.More-substituted allenes also undergo silyl-cupration followed by protonation, phenylallenes giving vinylsilanes, and alkylallenes giving, on the whole, allylsilanes.Stoichiometric stannyl-cupration of allenes takes place, with similar but less reliable regiocontrol to that of the corresponding silyl-cupration.