手性二胺的銅配合物催化α-酮酸酯不對稱Henry反應(yīng)的研究.pdf

1、華中科技大學(xué)碩士學(xué)位論文手性二胺的銅配合物催化α-酮酸酯不對稱Henry反應(yīng)的研究姓名：董俊芳申請學(xué)位級別：碩士專業(yè)：有機(jī)化學(xué)指導(dǎo)教師：龔躍法2011-01-11華 中 科 技 大 學(xué) 碩 士 學(xué) 位 論 文 華 中 科 技 大 學(xué) 碩 士 學(xué) 位 論 文 IIAbstract The asymmertric Henry reaction of α-ketoesters with nitromethane that provides

2、straightforward access to β-nitro α-hydroxy esters containing chiral quaternary carbon center represents a powerful C–C bond-forming tool, and the resulting multi-functional products can be transformed into compounds suc

3、h as β-amino α-hydroxy esters, α-lactams and aziridines which are highly useful compounds in organic chemistry. However, there are only fourteen papers with regard to the catalytic asymmetric Henry reaction of α-ketoeste

4、rs since the first example that was reported by Jørgensen in 2001. Besides, most of the results in these papers are not so satisfactory with only moderate to good yields and enantioselectivities. Thus, opportunities

5、 as well as challenges triggered us to carry out the work. In this thesis, we delineate the development of the enantioselective Henry reaction of α-keto esters with nitromethane catalyzed by copper (II) salts in combinat

6、ion with chiral diamine ligands in the presence of base additives. Firstly, we chose the reaction of ethyl pyruvate with nitromethane as the model reaction to screen a series of C1 symmetric diamine ligands. It was found

7、 that ligands with two secondary amines were superior to other diamine ligands in terms of enantioselectivity and L7 gave the most promising result. To the best of our knowledge, no report has been made on Henry reaction

8、 of α-ketoesters that was catalyzed by diamine ligands with two secondary amines. Secondly, optimizations of the reaction parameters were carried out systematically, such as metal salts, solvents, base additives and thei

9、r amounts. The standard conditions were established as follows: α-ketoesters and nitromethane reacted in the presence of 20 mol% Cu(OTf)2 in combination with 20 mol% L7 and 25 mol% N-methyl morpholine as base additive in