Remarkable tolerance of ethynyl steroids to air and water in microwave-assisted hydrophosphinylation: Reaction scope and limitations

The microwave-assisted hydrophosphinylation of propargyl alcohols has been investigated using group 9 catalysts under solvent-free conditions as well as with pure water, ethyl lactate, or THF as the solvent. Reactions involving simple propargyl alcohols gave mixtures containing significant amounts of elimination products. In contrast, analogous reactions involving ethynyl steroids afforded a single species with only trace amounts of elimination products. The molecular structures of several derivatives have been determined and are discussed.