A new, rapid, and high-yield synthesis of borane adducts with amines and phosphines has been developed. It is based on the reaction of sodium borohydride and iodine in the presence of the donor. The procedure is applicable to adducts of ammonia, primary, secondary, and tertiary amines, di- and triamines, pyridines, triphenylphosphine, and diphosphines. The following new compounds have been prepared: 2-methoxypyridine-borane, 2,2′-dipyridyl-bis(borane), bis(diphenylphosphino) methane-bis(borane), and 1,2-bis(diphenylphosphino)ethane-bis(borane). © 1969, American Chemical Society. All rights reserved.