Tertiary phosphines are prepared by reacting a phosphine (PH3 or a primary or secondary phosphine) with a cyclic alpha,beta-unsaturated carbonyl compound having no more than one C═C double bond conjugated with a carbonyl group. The inventive tertiary phosphines can have R groups that are the same or different. The inventive tertiary phosphines may be used as ligands for metal catalysts or as starting materials for preparing phosphonium salts or ylids.