Palladium(ii)-catalyzed asymmetric hydrophosphination of enones: efficient access to chiral tertiary phosphines

Abstract

Chiral tertiary phosphines were synthesized by asymmetric hydrophosphination of aromatic enones catalyzed by an organopalladium complex with high yields and stereoselectivity. The procedure offers practical access to chiral tertiary phosphines.

Challenges in Catalytic Hydrophosphination

“…The groups of Leung, Pullarkat, and Duan have extensively studied the development of palladium‐catalyzed hydrophosphination to generate C‐chiral phosphine products . A report from Leung and co‐workers appeared almost simultaneously with one from Duan and co‐workers for the hydrophosphination of enones with secondary phosphines by using palladium catalysts to achieve ee values of up to 99 % [Eq. ()].…”

Palladacycle‐Catalyzed Tandem Allylic Amination/Allylation Protocol for One‐Pot Synthesis of 2‐Allylanilines from Allylic Alcohols

“…[25] We have also recently reported their efficacy in C À P bond formation reactions. [26] We report here the catalytic properties of a simple cationic palladacycle ( Figure 1) which is readily derived from the…”

Palladacycle Catalyzed Asymmetric PH Addition of Diarylphosphines to N‐Enoyl Phthalimides

“…We began our studies with the introduction of successively more potent electron‐withdrawing groups to cinnamide 1 in an attempt to reduce the localisation of nitrogen’s electron in the conjugated olefin system. Whereas 1 was expected to be relatively inert to nucleophilic attack, substrates 2 , 3 and 4 also showed no desired conversion18 with diphenylphosphine (Ph 2 PH) 6 w in the presence of catalyst ( R )‐ 7 , which is a chiral palladacycle that has been demonstrated to function as an efficient and versatile catalyst in a number of reactions 6b,c,e. 8, 9a, 12, 19–21 Determined to overcome the challenge, we introduced the phthalimido group for, to our knowledge, the first time, hoping to achieve our desired objective.…”