Asymmetric synthesis of functionalized 1,3-diphosphines via chiral palladium complex promoted hydrophosphination of activated olefins.
Aldehyde, ester- and keto-functionalized monophosphine palladium complexes containing the ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary and reaction promoter were synthesized via hydrophosphination of acrolein and the subsequent Wittig reactions in a one-pot process. Under very mild conditions, the second-stage hydrophosphination of the monophosphine substrates gave the corresponding ester-, keto-, and hydroxyl-functionalized chiral 1,3-bis(diphenylphosphino)propane palladium complexes with good yields and stereoselectivities. The coordination properties and absolute configurations of the novel 1,3-diphosphine complexes were established by single crystal X-ray crystallography. The enantiomerically pure functionalized diphosphine ligands with ester and keto functionalities could be subsequently liberated stereospecifically by treatment of the corresponding dichloro palladium complexes with aqueous potassium cyanide in high yields.
Yuan
Mingjun
M
Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Zhang
Na
N
Pullarkat
Sumod A
SA
Li
Yongxin
Y
Liu
Fengli
F
Pham
Phuong-Tu
PT
Leung
Pak-Hing
PH
D000475:Alkenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010720:Phosphines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000475:Alkenes; D009942:Organometallic Compounds; D010720:Phosphines; D010165:Palladium