Diastereoselective and Enantioselective Hydrophosphinylations of Conjugated Enynes, Allenes and Dienes via Synergistic Pd/Co Catalysis

Abstract Different from the reported work focusing on the construction of single P ‐ or C ‐stereocenter via hydrophosphinylation of unsaturated carbon bonds, the highly diastereo‐ and enantioselective hydrophosphinylation reaction of allenes, conjugated enynes and 1,3‐dienes is achieved via a designed Pd/Co dual catalysis and newly modified masked phosphinylating reagent. A series of allyl motifs bearing both a tertiary C ‐ and P ‐stereocenter are prepared in generally good yields, >20 : 1 dr, >20 : 1 rr and 99 % ee. The unprecedented diastereo‐ and enantioselective hydrophosphinylation of 1,3‐enynes is established to generate skeletons containing both a P ‐stereocenter and a nonadjacent chiral axis. The first stereodivergent hydrophosphinylation reaction is also developed to achieve all four P ‐containing stereoisomers. The present protocol features the use of only 3‐minutes reaction time and 0.1 % catalyst, and with the observation of up to 730 TON. A set of mechanistic studies reveal the necessity and roles of two metal catalysts and corroborate the designed synergistic process.