Patent ID: 6635784
Filing Date: 2003-10-21
Classification: C07B,C07C,C07D,C07F

Abstract:
A process for the preparation of an enantiomerically-enriched cyclopropylalanine compound having the formula which comprises contacting an enamide having the formula â€ƒwith hydrogen in the presence of a catalyst system comprising a transition metal and a substantially enantiomerically-pure bis-phosphine under hydrogenation conditions of pressure and temperature; wherein R1 is hydrogen, substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C1 to C20 alkoxy, substituted or unsubstituted C3 to C8 cycloalkyl, substituted or unsubstituted C3 to C8 cycloalkoxy, substituted or unsubstituted carbocyclic C6 to C20 aryl, substituted or unsubstituted carbocyclic C6 to C20 aryloxy, substituted or unsubstituted C4 to C20 heteroaryl wherein the heteroatoms are selected from sulfur, nitrogen, and oxygen or substituted or unsubstituted C4 to C20 heteroaryloxy wherein the heteroatoms are selected from sulfur, nitrogen, and oxygen; R2 is hydrogen, unsubstituted or substituted C1 to C20 alkyl, substituted or unsubstituted C3 to C8 cycloalkyl, unsubstituted or substituted carbocyclic C6 to C20 aryl, or substituted or unsubstituted C4 to C20 heteroaryl wherein the heteroatoms are selected from sulfur, nitrogen, and oxygen; and the bis-phosphine has the formula wherein R5 is selected from substituted and unsubstituted, branched- and straight-chain C1 to C20 alkyl, substituted and unsubstituted C3 to C8 cycloalkyl, substituted and unsubstituted C6 to C20 carbocyclic aryl, and substituted and unsubstituted C4 to C20 heteroaryl wherein the heteroatoms are selected from sulfur, nitrogen, and oxygen; R6, R7, R8, R9, and R10 are independently selected from hydrogen, substituted and unsubstituted, branched- and straight-chain C1 to C20 alkyl, substituted and unsubstituted C3 to C8 cycloalkyl, substituted and unsubstituted C6 to C20 carbocyclic aryl, and substituted and unsubstituted C4 to C20 heteroaryl wherein the heteroatoms are selected from sulfur, nitrogen, and oxygen; n is 0 to 3; m is 0 to 5; and M2 is selected from the metals of Groups IVB, VB, VIB, VIIB and VIII.