DIASTEREOFACE DIFFERENTIATING (NET) HYDRIDE TRANSFER IN NOVEL 5-DEAZAFLAVINS MODIFIED AT PYRIMIDINE RING

In novel 5-deazaflavin models (1)-(5) where one face of the pyrimidine ring moiety is flanked, "(net) hydride transfer" from BNAH occurred at mainly C(5) on the face which aligns with the open side of the pyrimidine ring. The degree of diastereoface differentiation depends on the bulkiness of the substituent on phenyl group at N(3). The results revealed that the pyrimidine Ting moiety of flavin ring system interacts with the carbamoyl group of BNAH in the transition state of the "(net) hydride transfer" reaction. Diastereoface differentiating "(net) hydride abstraction" from the reduced 5-deazaflavin was also investigated.