In some cases phosphorus-containing ligands inhibit the hydroxide-promoted reactions of metal carbonyl halides with allyl bromide; a rationale involving decreased acidity of the carbonyl ligands is presented. Syntheses of η 3-C 3H 5Mn(CO) 3P(OCH 3) 3 and η 3-C 3H 5Mn(CO) 2[P(OCH 3) ...