摘要
采用改进的方法,以NaH作为碱,在温和条件下通过二氢奎尼丁和3,6二氯哒嗪的亲核取代反应合成了手性配体3,6双(9O二氢奎尼丁)哒嗪((DHQD)2PYDZ),配体的产率为78%.以N氯代氨基甲酸苄酯钠为氧化供氮试剂,由(DHQD)2PYDZ与OsO4原位生成的催化剂在6种烯烃的不对称氨羟化反应中表现出较高的立体选择性(83%～92%)和区域选择性(79∶21～88∶12),反应主产物的化学产率为40%～76%.
The asymmetric aminohydroxylation (AA) of olefins using catalytic amounts of potassium osmate in the presence of cinchona alkaloid derivatives has become the most powerful method for the preparation of a wide variety of enantiomerically pure beta-amino, alcohols. To improve the chemo-, regio- and enantioselectivity of this reaction and lower the cost, chiral ligand 316-bis(9-O-dihydroquinidine)pyridazine ((DHQD)(2)PYDZ) was synthesized by a modified method and applied to the AA reaction. The synthesis of (DHQD)2PYDZ was completed by the nucleophilic substitution of 3,6-dichloropyridazine by dihydroquinidine with a 78% yield in the presence of NaH. Using complex (DHQD)(2)PYDZ-OsO4 as catalyst and N-chlorocarbamate as oxidant and nitrogen source, the AA reaction of six olefins (styrene, methyl cinnamate, ethyl cinnamate, iso-propyl cinnamate, beta-vinylnaphthalene and 4-chlorostyrene) gave high enantioselectivity (83 % similar to 92 % ee) and regioselectivity (79: 21 similar to 88: 12), and the chemical yield was 40 % similar to 76 %. The major regioisomers were beta-amino acid esters.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2005年第7期621-624,共4页
基金
国家自然科学基金资助项目(20372083
20302014).
