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1. A process using a phase transfer catalyst comprising a bis-quaternary cinchona alkaloid salt having the chemical structure of Formula I:wherein:
R1 is selected from ethyl and vinyl, R2 is selected from hydrogen and methoxy, R3 and R4 are independently selected from the group consisting of C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C3-6cycloalkyl, aryl, heteroaryl, —C1-4alkyl-aryl and —C1-4alkyl-heteroaryl, wherein C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C3-6cycloalkyl, aryl, heteroaryl and the aryl and heteroaryl portions of —C1-4alkyl-aryl and —C1-4alkyl-heteroaryl are optionally substituted with one to five substituents independently selected from R6, R5 is selected from the group consisting of hydrogen, C(O)R, C(O)OR, CONRR′, and C1-6-alkyl, R6 is selected from the group consisting of C1-4alkyl, C1-4haloalkyl, aryl, C1-4alkoxy, hydroxy, CN, CO2R, CONRR′, SR, SO2R, SO3R, PR2, PO(OR)2, PO(OR)(NRR′), PO(NRR′)2, P(OR)2, P(OR)(NRR′), P(NRR′)2, SiRR′R″, B(OR)2, C(O)R, NRR′, NO2, and halogen, each R, R′ and R″ is independently selected from the group consisting of, H, C1-6alkyl, hydroxyl, C1-6alkoxy, aryl, heteroaryl, —CH2-aryl, —CH2-heteroaryl, and each X and Y are independently anions selected from halide, OH, HSO4, SO4, BF4, SbF6, carboxylate, carbonate, hydrogencarbonate, NO3, sulfonate, hexafluorophosphate, phosphate, hydrogen phosphate and perchlorate, wherein said phase transfer catalyst is used to provide the stereoselective formation of a carbon-carbon, carbon-heteroatom or carbon-halide bond on a substrate in a biphasic medium comprising an aqueous phase and organic phase or a micelle medium. |
