当前位置：
X-MOL 学术
›
ACS Catal.
›
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.)
Visible-Light-Driven Reductive (Cyclo)Dimerization of Chalcones over Heterogeneous Carbon Nitride Photocatalyst
ACS Catalysis ( IF 11.3 ) Pub Date : 2019-01-17 00:00:00 , DOI: 10.1021/acscatal.8b04182 Bogdan Kurpil 1 , Yevheniia Markushyna 1 , Aleksandr Savateev 1
ACS Catalysis ( IF 11.3 ) Pub Date : 2019-01-17 00:00:00 , DOI: 10.1021/acscatal.8b04182 Bogdan Kurpil 1 , Yevheniia Markushyna 1 , Aleksandr Savateev 1
Affiliation
|
Single-electron reduction of chalcones to the respective radical anions is a useful technique to activate these molecules toward subsequent transformations. Herein, a metal-free photocatalytic version of chalcones reduction in the presence of triethanolamine as a convenient electron donor and using heterogeneous carbon nitride visible-light photocatalyst is presented. The reaction proceeds via a long-lived radical species of the heterogeneous organic semiconductor. The scope of the reaction was studied, and regioselectivity of the chalcone radicals coupling was investigated. (1) Ten chalcones gave selectively polysubstituted cyclopentanoles with 31–73% isolated yield; (2) Two chalcones bearing electron-donor groups, 4-MeOC6H4 and 2-thienyl, gave selectively the β-ketodienes in 42% and 53% isolated yield, respectively; (3) Pentafluorophenyl substituted chalcone gave exclusively the product of the radicals coupling followed by hydrogen transfer from triethanolamine–hexane-1,6-dione in 65% isolated yield. Reductive cross cyclodimerization of a mixture of two different chalcones proceeded regioselectively with the formation of one product out of four possible. The mechanism was investigated by cyclic voltammetry and linear sweep voltammetry and suggests that the reaction proceeds through proton-coupled electron transfer.
中文翻译：
异质氮化碳光催化剂上Ch的可见光驱动还原（环）二聚反应
查耳酮单电子还原为相应的自由基阴离子是激活这些分子进行后续转化的有用技术。在此，提出了在三乙醇胺作为方便的电子供体存在下并使用非均相氮化碳可见光光催化剂还原查尔酮的无金属光催化方案。该反应通过异质有机半导体的长寿命自由基种类进行。研究了反应的范围，并研究了查耳酮自由基偶联的区域选择性。（1）十个查耳酮生成选择性多取代的环戊醇，分离产率为31-73％；（2）两个带有电子给体基团的查耳酮，4-MeOC 6 H 4和2-噻吩基分别产生β-酮二烯，分离产率分别为42％和53％。（3）五氟苯基取代的查尔酮仅给出自由基偶联的产物，然后从三乙醇胺-己烷-1,6-二酮中转移氢，分离出产率为65％。两种不同查耳酮混合物的还原性交叉环二聚反应区域选择性地进行，形成了四种可能产物中的一种。通过循环伏安法和线性扫描伏安法研究了该机理，表明该反应通过质子偶联电子转移进行。
更新日期：2019-01-17
中文翻译：
异质氮化碳光催化剂上Ch的可见光驱动还原（环）二聚反应
查耳酮单电子还原为相应的自由基阴离子是激活这些分子进行后续转化的有用技术。在此，提出了在三乙醇胺作为方便的电子供体存在下并使用非均相氮化碳可见光光催化剂还原查尔酮的无金属光催化方案。该反应通过异质有机半导体的长寿命自由基种类进行。研究了反应的范围，并研究了查耳酮自由基偶联的区域选择性。（1）十个查耳酮生成选择性多取代的环戊醇，分离产率为31-73％；（2）两个带有电子给体基团的查耳酮，4-MeOC 6 H 4和2-噻吩基分别产生β-酮二烯，分离产率分别为42％和53％。（3）五氟苯基取代的查尔酮仅给出自由基偶联的产物，然后从三乙醇胺-己烷-1,6-二酮中转移氢，分离出产率为65％。两种不同查耳酮混合物的还原性交叉环二聚反应区域选择性地进行，形成了四种可能产物中的一种。通过循环伏安法和线性扫描伏安法研究了该机理，表明该反应通过质子偶联电子转移进行。
京公网安备 11010802027423号