Stable dithioxophosphorane, diselenoxophosphorane, and selenoxophosphine bearing 2,4-Di-t-butyl- 6-(dimethylamino)phenyl group as a new sterically protecting auxiliary

2,4-Di-t-butyl-6-(dimethylamino)phenylphosphonous dichloride was prepared from 2-bromo-3,5-di-t- butyl,-N,N-dimethylaniline. The dichloride was then converted to the corresponding diphosphene. The reaction of the diphosphene with sulfur or selenium in triethylamine afforded 2,4-di-t-butyl-6-(dimethylamino)- phenyldithioxophosphorane or diselenoxophosphorane,respectively, as a very stable compound and the diselenoxophosphorane was deselenated with hexamethylphosphorous triamide to give selenoxophospine.