Synthesis of 1,4-Dihydro-2H-3,1-benzoxazin-2-ones by Hydriodic Acid Mediated Cyclization of tert-Butyl 2-Vinylphenylcarbamates
摘要:
A two-step facile synthesis of 4,4-disubstituted 1,4-dihydro-2H-3,1-benzoxazin-2-ones starting from alpha-substituted 2-aminostyrenes is described. The method involves the hydriodic acid mediated cyclization of t-butyl 2-vinylphenylcarbamate derivatives, which Could be easily prepared by N-t-butoxycarbonylation of alpha-substituted 2-aminostyrene derivatives, under mild conditions.
It has been found that t-butyl 2-vinylphenylcarbamate derivatives underwent iodocyclization on treatment with iodine in the presence of sodium hydrogencarbonate to afford 4-iodomethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one derivatives in generally good yields. The reduction of these 4-iodomethyl derivatives with tributyltin hydride gave the corresponding 4-methyl derivatives in good yields.
Catalytic Asymmetric Chlorocyclization of 2-Vinylphenylcarbamates for Synthesis of 1,4-Dihydro-2<i>H</i>-3,1-benzoxazin-2-one Derivatives
作者:Yan-Min Yu、Ya-Nan Huang、Jun Deng
DOI:10.1021/acs.orglett.7b00272
日期:2017.3.3
A facile synthetic approach to a series of chiral 4-chloromethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one derivatives has been described. This transformation is achieved through the catalyticasymmetric chlorocyclization of 2-vinylphenylcarbamates using a newly developed organocatalyst. Furthermore, the resulting products can be easily converted into diverse bioactive agents.
已经描述了对一系列手性4-氯甲基-1,4-二氢-2 H -3,1-苯并恶嗪-2-酮衍生物的简便合成方法。通过使用新开发的有机催化剂对2-乙烯基苯基氨基甲酸酯进行催化不对称氯环化来实现这种转化。此外,所得产物可以容易地转化为多种生物活性剂。
Synthesis of 1,4-Dihydro-2H-3,1-benzoxazin-2-ones by Hydriodic Acid Mediated Cyclization of tert-Butyl 2-Vinylphenylcarbamates
A two-step facile synthesis of 4,4-disubstituted 1,4-dihydro-2H-3,1-benzoxazin-2-ones starting from alpha-substituted 2-aminostyrenes is described. The method involves the hydriodic acid mediated cyclization of t-butyl 2-vinylphenylcarbamate derivatives, which Could be easily prepared by N-t-butoxycarbonylation of alpha-substituted 2-aminostyrene derivatives, under mild conditions.