Suzuki Cross-Coupling on Enantiomerically Pure Epoxides: Efficient Synthesis of Diverse, Modular Amino Alcohols from Single Enantiopure Precursors

摘要

Suzuki arylation of enantiopure (4-bromophenyl)- or (3,5-dibromophenyl)glycidyl ethers has been achieved in toluene under Buchwald conditions [ArB(OH)_2 (1.1 equiv), Cs_2CO_3 (2 equiv), Pd_2(dba)_3·C_6H_6 (1 mol %), S-Phos (4 mol %), toluene, 100℃] allowing for the formation of modular arylglycidyl ethers not directly available in enantiopure form by epoxidation routes. These bulky ethers, when submitted to regioselective and stereospecific ring opening with ammonia [aq NH_3, LiClO_4 (1 equiv), THF, microwave irradiation (80 W), 125℃] in a sealed tube, provide access to novel enantiopure β-amino alcohols which, in turn, provide an easy access to structurally complex C_2 symmetrical bisoxazolines.