Chiral 1,2-Diaminocyclohexane-α-Amino Acid-Derived Amidphos/Ag(I)-Catalyzed Divergent Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Ylides
Jie Luo, Youshi Liu, Haifei Wang, Chuliang Gong, Zhipeng Zhou, Qingxia Zhou
Abstract
A series of chiral 1,2-diaminocyclohexane--amino acid-derived amidophosphanes in combination with silver(I) salts, have been developed to cooperatively catalyze the azomethine ylides-involved 1,3-dipolar cycloaddition with different electron-deficient alkenes. Among these, the (1S,2S)-1,2-cyclohexanediamine-L-tert-leucine-derived amidphos/Ag(I) has been demonstrated as being a highly efficient catalytic system in the cis-1,2-disubstituted electron-deficient olefins-involved 1,3-dipolar cycloaddition of azomethine ylides, including a series of aromatic, heteroaromatic, aliphatic, and 2-substituted azomethine ylides, affording various fully substituted pyrrolidines in high to excellent yields (up to 97% yield) and enantioselectivities (up to 97% ee).