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烷基锌促进末端炔与亚胺的不对称加成反应研究

Dialkylzinc Promoted Asymmetric Addition of Terminal Alkynes to Imines

【作者】 尹超

【导师】 许鹏飞;

【作者基本信息】 兰州大学 , 有机化学, 2010, 博士

【摘要】 末端炔对C=O和C=N双键的不对称加成反应是近年来有机合成研究领域的热点之一,本文主要讨论了C2对称β-羟基酰胺类配体的合成及在不对称催化苯乙炔和醛的加成反应中的应用,以及二烷基锌促进的末端炔对手性叔丁基亚磺酰亚胺和对甲基苯磺酰亚胺的不对称加成反应研究。本论文包括以下四个部分:1.炔丙胺是合成天然产物、药物和复杂有机分子的重要砌块,在天然产物全合成和药物合成中可以作为关键中间体,本章对近年来金属催化的末端炔烃对C=N双键的加成反应研究进行了总结。2.以天然氨基酸为原料,设计合成了一系列C2对称β-羟基酰胺类手性配体,并将其应用于催化苯乙炔对醛的不对称加成反应,实验发现ZnEt2.Ti(OPr)4和溶剂对催化效果有非常大的影响,经过一系列条件优化,获得了很好的产率(82-94%yield)和较高的ee值(52-98%ee)。3.首次报道了二乙基锌促进的末端炔对手性叔丁基亚磺酰亚胺的不对称加成合成2-烯基-3-炔基胺。二乙基锌与末端炔首先生成炔基锌,在回流条件下与亚胺进行加成反应得到目标产物,该反应对芳香族及脂肪族的炔和亚胺都有很好的适用性,以最高94%的产率和>99:1的非对映选择性得到了目标产物;通过X-单晶衍射确定了产物的绝对构型;并在对反应机理研究的基础上提出了一个合理的机理。4.首次报道了二甲基锌和BINOL类配体不对称催化末端炔与对甲基苯磺酰亚胺的加成反应,在最佳条件下,考察了不同炔对芳香族和杂芳香族对甲基苯磺酰亚胺的加成,以很高的产率(51-92%yield)和很好的ee值(82-99%ee)得到了2-烯基-3-炔基胺;通过改变炔的加入顺序实现了两分子不同炔对亚胺加成的选择性问题。

【Abstract】 The catalytic addition of terminal alkynes to C=O and C=N double bond is one of the major research endevors in synthetic chemistry over the past decades. In this paper, we mainly discuss the design and synthesis of some new C2-symmetric bis(β-hydroxy amide) ligands and their applications in the enantioselective addition of alkynylzinc to aldehydes, and dialkylzinc promoted asymmetric addition of alkynes to chiral N-tert-butylsulfinylimines and N-tosylaldimines. This thesis is composed of four parts as below:1. Propargylic amines are highly useful building blocks in organic synthesis. This part provides an overview of the most significant advances in the preparation of propargylic amines via the direct addition of alkynes to imines and carbon nitrogen electrophiles in the presence of metal catalysts or promoters.2. A series of chiral C2-symmetric bis(β-hydroxy amide) ligands was synthesized via the reaction of isophthaloyl dichloride and amino alcohols derived from L-amino acids. The amount of ZnEt2, Ti(O’Pr)4 and solvents had a strong effect on the asymmetric alkynylation of aldehydes, and the propargyl alcohols were obtained in high yields (82-94% yield) and high enantiomeric excesses (52-98% ee) under optimized conditions.3. The first direct approach for the asymmetric synthesis of (E)-2-arylidene-1,4-diphenylbut-3-yn-l-amines by addition of alkynylzinc to chiral N-tert-butyl-sulfinylimines was reported. The alkynylzinc was formed in situ from dialkylzinc and terminal alkynes reacted with imines under reflux conditions affording the disired products. Following this methodology, a number combination of various alkynes and imines to give the products with excellent diastereoselectivitis and good yields (up to 92% yield and up to>99:1 dr). The stereochemistry of the compounds was determined by X-ray crystallography. On the basis of a number of experimental observations, we gave an explanation for the new reaction mechanism. 4. We have reported the first procedure for the catalytic enantioselective additon of terminal alkynes to N-tosylaldimines to give N-tosyl-(E)-(2-en-3-ynyl)-amines by using dimethylzinc and BINOL-type ligands. The reaction works with a variety of aromatic and heteroaromatic N-tosylaldimines, and with different alkynes, providing the expected products with good yields (51-92% yield) and high enantiomeric excesses (82-99% ee). In particular, this method could be used to deal with two different alkynes to give diversified products successfully.

  • 【网络出版投稿人】 兰州大学
  • 【网络出版年期】2010年 10期
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