申请人:Zhang Wanbin
公开号:US20090043104A1
公开(公告)日:2009-02-12
The present invention relates to a method for preparing 2,2′,6,6′-tetraoxazolinyl biphenyl ligand in chemical industry field. In the present invention, compound (III) is reacted with an activator that can activate the hydroxyl group selected from the group consisting of alkyl halosulfonium compound, aryl halosulfonium compound, phosphoryl chloride, phosphorus pentachloride, thionyl chloride and triphenyl phosphine, in the presence of alkali(s), to give the target product (IV), 2,2′,6,6′-tetraoxazolinyl biphenyl ligand. The ligand of the present invention can be used in various asymmetric reactions catalyzed by metals, with high reactivity and stereoselectivity, and thus represents a good application outlook. The 2,2′,6,6′-tetraoxazolinyl biphenyl ligand has the formula of:
wherein, R
1
=hydrogen, alkyl, substituted or unsubstituted aryl, substituted or unsubstituted benzyl; R
2
=hydrogen, alkyl, substituted or unsubstituted aryl, substituted or unsubstituted benzyl; R
3
=hydrogen, alkyl, substituted or unsubstituted aryl, substituted or unsubstituted benzyl; R
4
=hydrogen, alkyl, substituted or unsubstituted aryl, substituted or unsubstituted benzyl.
本发明涉及一种在化工领域制备2,2′,6,6′-四氧杂环己基联苯配体的方法。在本发明中,化合物(III)与可以激活羟基的活化剂发生反应,所述活化剂选自烷基卤磺酸盐化合物、芳基卤磺酸盐化合物、氯代磷酰氯、五氯化磷、氯化亚硫酰和三苯基膦组成的群体,并在碱的存在下,得到目标产物(IV),即2,2′,6,6′-四氧杂环己基联苯配体。本发明的配体可用于由金属催化的各种不对称反应中,具有高反应性和立体选择性,因此具有良好的应用前景。2,2′,6,6′-四氧杂环己基联苯配体的化学式为:其中,R1=氢、烷基、取代或未取代芳基、取代或未取代苄基;R2=氢、烷基、取代或未取代芳基、取代或未取代苄基;R3=氢、烷基、取代或未取代芳基、取代或未取代苄基;R4=氢、烷基、取代或未取代芳基、取代或未取代苄基。