One-pot synthesis of imidazolines from aldehydes: detailed study about solvents and substrates
摘要:
Imidazolines were prepared in one-pot operation from aldehydes and diamines through oxidation of aminal intermediates by NBS. This method could be applied to various aromatic and aliphatic aldehydes and N-nonsubstituted and N-monosubstituted 1,2-diamines. Furthermore, it was found that CH2Cl2 could be altered to TBME, a more environmentally friendly solvent, in the reaction using N-nonsubstituted 1,2-diamines. The reaction conditions were very mild and chemoselective. (c) 2006 Published by Elsevier Ltd.
本报告描述了在金鸡纳生物碱胺存在下2-亚烷基苯并[ b ]噻吩酮衍生物与烯酮之间的有机催化级联反应。通过一步合成,制备了包含三个立体中心的螺苯并噻吩苯甲酸环己烷衍生物,其产率为88%至96%,对映选择性(对映体过量(ee))为85至97%,非对映选择性约为14/2/1。因此,该方法为合成新型的光学活性的2-螺苯并噻吩酮提供了有效的途径。
Chiral Primary−Tertiary Diamine Catalysts Derived From Natural Amino Acids for <i>syn</i>-Aldol Reactions of Hydroxy Ketones
作者:Jiuyuan Li、Sanzhong Luo、Jin-Pei Cheng
DOI:10.1021/jo802557p
日期:2009.2.20
A series of primary-tertiary diamine catalysts were designed and synthesized from primary natural amino acids. Application of these new chiral catalysts in direct aldol reactions of α-hydroxyketones showed very good catalytic activity (up to 97% yield) and high syn selectivity (up to syn/ anti = 30:1, 99% ee).
从伯天然氨基酸设计合成了一系列伯叔二胺催化剂。这些新的手性催化剂在α-羟基酮的直接醛醇缩合反应中的应用显示出非常好的催化活性(高达97%的收率)和高的合成选择性(高达syn / anti = 30:1,99%ee)。
Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones Catalyzed by Primary-Secondary Diamines
作者:Yingpeng Lu、Changwu Zheng、Yingquan Yang、Gang Zhao、Gang Zou
DOI:10.1002/adsc.201100230
日期:2011.11
The asymmetric epoxidation of α,β-unsaturated ketones has been achieved by using functional and readily accessible primary-secondarydiamines as the catalysts, giving the useful alkyl epoxy products with good yields and high enantioselectivities (up to 99% ee).
Novel Syntheses of Enantiopure Hexahydroimidazo[1,5-<i>b</i>]isoquinolines and Tetrahydroimidazo[1,5-<i>b</i>]isoquinolin-1(5<i>H</i>)-ones via Iminium Cation Cyclizations
作者:Alan R. Katritzky、Kazuyuki Suzuki、Hai-Ying He
DOI:10.1021/jo0203241
日期:2002.11.1
Condensations of chiral diamines 11a-c with benzotriazole and formaldehyde gave benzotriazolyl intermediates 12a-c; similar condensations of alpha-amino-amides 10a-c with benzotriazole and paraformaldehyde gave 14a-c. Subsequent treatment of 12a-c and 14a-c with AlCl3 led to enantiopure tricyclic 1,2,3,5,10,10a-hexahydroimidazo[1,5-b]isoquinolines 1a-c and 2,3,10,10a-tetrahydroimidazo[1,5-b]isoquinolin-1(5H)-ones 15a-c, respectively, via Lewis acid promoted iminium cation cyclizations.