(R)-和(S)-硝苯洛尔的不对称催化合成

Catalytic Asymmetric Synthesis of (R)-and (S)-Nifenalols

以4-硝基苯乙酮为原料,经溴化、还原和闭环反应生成外消旋的4-硝基环氧苯乙烷,经手性(R,R)-Salen-Co(Ⅲ)催化剂催化水解动力学拆分(HKR)得到(R)-4-硝基环氧苯乙酮和(S)-1-(4-硝基苯基)-1,2-乙二醇。环氧中间体经异丙胺作用生成(R)-硝苯洛尔,所得到的二醇先与氯化亚砜作用生成环状亚硫酸酯,再与异丙胺反应得到(S)-硝苯洛尔。产物结构经1HNMR、IR、MS表征。

Racemic 4-nitrostyrene oxide was synthesized by using 4-nitroacetophenone,which subjected to brominate,reduction and subsequent ring-closing reaction.（ R）-4-Nitrostyrene oxide and（ S）-1-（ 4-nitrophenyl）-1,2-ethanediol were obtained by the hydrolytic kinetic resolution（ HKR） of racemic 4-nitrostyrene oxide using chiral（ R,R）-salen-Co（ Ⅲ）as the catalyst. The epoxide reacted with isopropylamine to create（ R）-nifenalol. The diol firstly treated with thionyl chloride to form cyclic sulfite,and then via nucleophilic ringopening of isopropylamine to obtained（ S）-nifenalol. The structures were confirmed by1 HNMR,IR and MS.