The Spiro Single Phosphorus Ligand In The ¦Á-alkyl Substituted In The Catalytic Asymmetric Hydrogenation Of Ene Amide,

Chiral amine is an essential structural unit in natural products and a key function group in many biologically active molecules. Rhodium-catalyzed asymmetric hydrogenation of enamides is one of the most efficient methods to produce chiral primary and secondary amine derivatives. Althought significant progresses have been achieved in transition metal-catalyzed highly enantioselective hydrogenation ofα-aryl enamines in the past decades, few attention has been paid on asymmetric hydrogenation ofα-alkyl enamides. In this dissertation, we accomplished the rhodium-catalyzed asymmetric hydrogenation ofα-alkyl enamines using monodentate phosphorus ligands containing 1,1'-spirobiindane backbone.The monodentate spiro phosphonite ligands was successfully applies in rhodium -catalyzed asymmetric hydrogenation of (Z)-N-(1-phenylprop-1-en-2-yl)acetamide derivatives. Under the optimal reaction conditions the corresponding reducting product, tertiary amines were obtained in high yields with excellent enantioselectivities (up to 95% ee).Furthermore, rhodium-catalyzed asymmetric hydrogenation of (E)-N-(1-phenylprop-1-en-2-yl)acetamide derivatives was also investigated with monodentate spiro phospholane ligands, and the excellent enantioselectivities (up to 97% ee) have been achieved for a wide rang of substrate scopes. This is the first highly enantioselective hydrogenation of E-(α-alkyl)enamides. These work represents the first rhodium/monodentate phosphorus catalyzed highly enantioselective hydrogenation ofα-alkyl substituted enamides and provided an effective method to prepare chiralβ-aryliospropylamine derivatives.Eleven new compounds were synthesized in this thesis. Their structures were identified by 1H NMR, 13C NMR, HRMS or elemental analysis.