高等学校化学学报
高等學校化學學報
고등학교화학학보
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES
2014年
2期
297-302
,共6页
黎成勇%谭蓉%赵江峰%银董红
黎成勇%譚蓉%趙江峰%銀董紅
려성용%담용%조강봉%은동홍
对映选择性%离子液体%手性salen Mn(Ⅲ)配合物%不对称氧化动力学拆分%仲醇
對映選擇性%離子液體%手性salen Mn(Ⅲ)配閤物%不對稱氧化動力學拆分%仲醇
대영선택성%리자액체%수성salen Mn(Ⅲ)배합물%불대칭양화동역학탁분%중순
Enantioselectivity%Ionic liquid%Chiral salen Mn (Ⅲ) complex%Oxidation kinetic resolution%Secondary alcohol
采用共价键联法,将亲水性咪唑类离子液体结构引入手性salen Mn(Ⅲ)配合物的C5位,制备了离子液体功能化手性salen Mn(Ⅲ)配合物.傅里叶变换红外光谱、紫外光谱和旋光分析等结果表明,咪唑类离子液体结构已嫁接到手性salen Mn(Ⅲ)配合物结构中,且嫁接过程未破坏催化活性中心.在以PhI( OAc)2为氧化剂, H2 O/CH2 Cl2为溶剂的(+/-)-α-甲基苯甲醇不对称氧化动力学拆分反应中,该催化剂表现出比传统手性salen Mn(Ⅲ)催化剂更高的催化活性,仲醇的转化率达到63%以上,对映选择性为99%,拆分效率为18.3%.可通过调变溶剂实现催化剂的分离并重复使用3次以上.实验结果表明,亲水性咪唑离子液体可改善水相反应传质问题且有利于稳定催化活性中间体,从而提高催化活性及稳定性.
採用共價鍵聯法,將親水性咪唑類離子液體結構引入手性salen Mn(Ⅲ)配閤物的C5位,製備瞭離子液體功能化手性salen Mn(Ⅲ)配閤物.傅裏葉變換紅外光譜、紫外光譜和鏇光分析等結果錶明,咪唑類離子液體結構已嫁接到手性salen Mn(Ⅲ)配閤物結構中,且嫁接過程未破壞催化活性中心.在以PhI( OAc)2為氧化劑, H2 O/CH2 Cl2為溶劑的(+/-)-α-甲基苯甲醇不對稱氧化動力學拆分反應中,該催化劑錶現齣比傳統手性salen Mn(Ⅲ)催化劑更高的催化活性,仲醇的轉化率達到63%以上,對映選擇性為99%,拆分效率為18.3%.可通過調變溶劑實現催化劑的分離併重複使用3次以上.實驗結果錶明,親水性咪唑離子液體可改善水相反應傳質問題且有利于穩定催化活性中間體,從而提高催化活性及穩定性.
채용공개건련법,장친수성미서류리자액체결구인입수성salen Mn(Ⅲ)배합물적C5위,제비료리자액체공능화수성salen Mn(Ⅲ)배합물.부리협변환홍외광보、자외광보화선광분석등결과표명,미서류리자액체결구이가접도수성salen Mn(Ⅲ)배합물결구중,차가접과정미파배최화활성중심.재이PhI( OAc)2위양화제, H2 O/CH2 Cl2위용제적(+/-)-α-갑기분갑순불대칭양화동역학탁분반응중,해최화제표현출비전통수성salen Mn(Ⅲ)최화제경고적최화활성,중순적전화솔체도63%이상,대영선택성위99%,탁분효솔위18.3%.가통과조변용제실현최화제적분리병중복사용3차이상.실험결과표명,친수성미서리자액체가개선수상반응전질문제차유리우은정최화활성중간체,종이제고최화활성급은정성.
Hydrophilic imidazolium-based ionic liquid ( IL ) was introduced into the framework of the chiral salen Mn(Ⅲ) complex by covalent linkage, which provided a ionic liquid-functionalized chiral salen Mn(Ⅲ) complex. Fourier transform infrared spectrometry, UV-Vis and thermal analysis results showed that the chiral salen Mn(Ⅲ) complex was modified with the IL moiety with the intact active site. The catalytic performance of IL-functionalized chiral salen Mn (Ⅲ) complex in the asymmetric oxidation kinetic resolution ( OKR ) of secondary alcohols was investigated. It was found that the surfactant-type complex showed higher catalytic activity than neat chiral salen Mn(Ⅲ) complex. Secondary alcohol conversion was more than 63%, enantios-elective could reach 99% and separation efficiency was 18 . 3%. Catalyst could be facilely recovered from the reaction system for reuse 3 times by controlling solvent. The hydrophilic imidazolium-based IL was thought to improve the mass transfer associated with the aqueous reaction and stabilize the transition state, which in turns enhanced the activity and stability of the catalysts.