当前位置:
X-MOL 学术
›
React. Chem. Eng.
›
论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Continuous flow oxidation of benzylic and aliphatic alcohols using bleach: process improvement by precise pH adjustment in flow with CO2†
Reaction Chemistry & Engineering ( IF 3.9 ) Pub Date : 2018-01-23 00:00:00 , DOI: 10.1039/c7re00155j Laurent Vanoye 1, 2, 3, 4, 5 , Laurelle Yehouenou 1, 2, 3, 4, 5 , Régis Philippe 1, 2, 3, 4, 5 , Claude de Bellefon 1, 2, 3, 4, 5 , Pascal Fongarland 1, 2, 3, 4, 5 , Alain Favre-Réguillon 1, 2, 3, 4, 5
Reaction Chemistry & Engineering ( IF 3.9 ) Pub Date : 2018-01-23 00:00:00 , DOI: 10.1039/c7re00155j Laurent Vanoye 1, 2, 3, 4, 5 , Laurelle Yehouenou 1, 2, 3, 4, 5 , Régis Philippe 1, 2, 3, 4, 5 , Claude de Bellefon 1, 2, 3, 4, 5 , Pascal Fongarland 1, 2, 3, 4, 5 , Alain Favre-Réguillon 1, 2, 3, 4, 5
Affiliation
An improved method for the oxidation of benzylic and aliphatic alcohols using concentrated bleach (1.6 M NaOCl) using 2-step continuous flow microreactors is reported herein. Enhancement of the reaction rate was obtained by on-line pH adjustment. In the first step, the pH of the bleach was precisely decreased to pH 8.5 using CO2. Such pH is a compromise between oxidative properties, chemical stability and unwanted precipitation. The aqueous bleach solution was subsequently used for the oxidation of benzyl alcohols in EtOAc using catalytic amounts of TBAB (n-Bu4N+Br−) in a segmented flow microreactor. The total conversion of benzyl alcohols was obtained in less than 1 min using 2 eq. of NaOCl at r.t. without any metal catalysts. Selective benzyl alcohol oxidation (>98%) was demonstrated on primary and secondary alcohols. For aliphatic alcohols, 0.1 mol% TEMPO was used as a co-catalyst in synergy with TBAB and a total conversion with high selectivity (>98%) was achieved in less than 2 min.
中文翻译:
使用漂白剂对苄醇和脂肪醇进行连续流氧化:通过在CO 2 †中精确调节pH来改进工艺
本文报道了使用浓缩的漂白剂(1.6M NaOCl)并使用两步连续流微反应器氧化苄基和脂族醇的改进方法。通过在线调节pH可以提高反应速度。在第一步中,使用CO 2将漂白剂的pH精确降至pH 8.5 。这样的pH是氧化性质,化学稳定性和不希望的沉淀之间的折衷。含水漂白溶液随后用于苄醇类的EtOAc使用催化量的四丁基溴化铵(氧化Ñ -Bu 4 Ñ +溴-)在分段流动微反应器中。使用2 eq。不到1分钟即可获得苄醇的总转化率。室温下未加任何金属催化剂的NaOCl溶液。在伯醇和仲醇上证明了选择性苯甲醇氧化(> 98%)。对于脂族醇,与TBAB协同使用0.1 mol%TEMPO作为助催化剂,并在不到2分钟的时间内实现了高选择性(> 98%)的总转化率。
更新日期:2018-01-23
中文翻译:
使用漂白剂对苄醇和脂肪醇进行连续流氧化:通过在CO 2 †中精确调节pH来改进工艺
本文报道了使用浓缩的漂白剂(1.6M NaOCl)并使用两步连续流微反应器氧化苄基和脂族醇的改进方法。通过在线调节pH可以提高反应速度。在第一步中,使用CO 2将漂白剂的pH精确降至pH 8.5 。这样的pH是氧化性质,化学稳定性和不希望的沉淀之间的折衷。含水漂白溶液随后用于苄醇类的EtOAc使用催化量的四丁基溴化铵(氧化Ñ -Bu 4 Ñ +溴-)在分段流动微反应器中。使用2 eq。不到1分钟即可获得苄醇的总转化率。室温下未加任何金属催化剂的NaOCl溶液。在伯醇和仲醇上证明了选择性苯甲醇氧化(> 98%)。对于脂族醇,与TBAB协同使用0.1 mol%TEMPO作为助催化剂,并在不到2分钟的时间内实现了高选择性(> 98%)的总转化率。