Heterogeneous simplified Maruoka phase-transfer catalyst tethered on poly(styrene-co-acrylamide) microsphere: Structure-activity relationship in enantioselective α-alkylation
作者:Dandan Feng、Jingwei Wan、Fei Teng、Xuebing Ma
DOI:10.1016/j.catcom.2017.06.002
日期:2017.9
in heterogeneous α-alkylation. The catalyst poly[St-co-AA-co-(R)-11] with a rigid framework, where homogeneous (R)-11 was anchored at the 6, 6′-positions of binaphthyl skeleton, possessed the relatively larger surface area (33.5 m2 g− 1) and pore volume (1.27 cm3 g− 1) and displayed high yields (81–96%) and excellent enantioselectivities (96–97%ee) in enantioselectiveα-alkylation.
通过将Maruoka催化剂官能化的苯乙烯与EGDMA交联的苯乙烯和丙烯酰胺共聚,首次开发了有价值的简化Maruoka催化剂在不同位置共价固定在聚(苯乙烯-co-丙烯酰胺)微球上的方法。发现微球的形态,微孔特征和Maruoka催化剂的锚定位置是造成异质α-烷基化反应的主要因素。催化剂聚[步步骤骤共同-AA-共- ([R)-11]具有刚性框架,其中均质的(- [R)-11是在6,6'-位联萘骨架的锚定,所具有的相对较大的表面积(33.5 m2 g − 1)和孔体积(1.27 cm 3 g − 1),在对映选择性α-烷基化反应中显示出高收率(81–96%)和出色的对映选择性(96–97%ee)。
A New Class of Acetophenone-based Cinchona Alkaloids as Phase-transfer Catalysts: Application to the Enantioselective Synthesis of α-Amino Acids
作者:Jian Lv、Liping Zhang、Lei Liu、Yongmei Wang
DOI:10.1246/cl.2007.1354
日期:2007.11.5
A new class of acetophenone-based cinchona alkaloid-derived quaternary ammonium salts were prepared and evaluated as phase-transfercatalysts in the enantioselective alkylation of glycine imine est...
Merrifield resin supported cinchona ammonium salts bearing 2'-fluorobenzene, 2'-cyanobenzene and 2'-N-oxypyridine groups were prepared and applied to the phase-transfer catalytic alkylation of N-(diphenylmethylene)glycine tert-butyl ester for the enantioselective synthesis of alpha-amino acids (76-96% ee). (c) 2008 Elsevier Ltd. All rights reserved.
Synthesis of new dimeric-PEG-supported cinchona ammonium salts as chiral phase transfer catalysts for the alkylation of Schiff bases with water as the solvent
作者:Xin Wang、Liang Yin、Ting Yang、Yongmei Wang
DOI:10.1016/j.tetasy.2006.12.024
日期:2007.1
The water-soluble PEG-supported cinchona ammonium salts were successfully synthesized and used as chiral phase transfer catalysts for the asymmetric alkylation of tert-butyl benzophenone Schiff base derivatives with high chemical yields (up to 98%) and enantio selectivities (up to 97%) in aqueous media. The recycling results showed that the polymers were stable and rarely lost activities. (c) 2007 Elsevier Ltd. All rights reserved.
9-Amino-(9-deoxy)cinchona alkaloid-derived new chiral phase-transfer catalysts
作者:Wenwen Peng、Jingwei Wan、Bing Xie、Xuebing Ma
DOI:10.1039/c4ob01648c
日期:——
9-amino-(9-deoxy)cinchona alkaloid-derived chiralphase-transfercatalysts bearing amino groups was developed by using known cinchona alkaloids as the starting materials. Due to the transformation of the 9-hydroxyl group into a 9-amino functional group, the catalytic performances were significantly improved in comparison with the corresponding first generation phase-transfercatalysts, and excellent yields (92–99%)