文献类型：期刊文献

英文题名：Loading Phlorins with Fullerenes by a [4+2]-Cycloaddition Reaction: Regulation of the Regioselectivity by Pyrrole Linkage Modes

作者：Xue, Rongchao[1];Zhou, Yongzhu[1];Lin, Qianghao[2];Zhang, Lei[1];Li, Chengjie[2];Chen, Yu[1];Xie, Yongshu[2];Liu, Xiujun[2]

机构：[1]Tianjin Chengjian Univ, Sch Sci, Tianjin 300384, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China

年份：2022

卷号：87

期号：5

起止页码：2758

外文期刊名：JOURNAL OF ORGANIC CHEMISTRY

收录：;EI(收录号：20220811699487);WOS:【SCI-EXPANDED(收录号:WOS:000773458100054)】；

基金：We would like to thank the National Natural Science Foundation of China (NSFC 22108078, 22131005, 21808156, 21971063, and 22075077), the Natural Science Foundation of Shanghai (20ZR1414100), the Program of Shanghai Academic Research Leader (20XD1401400), and the Fundamental Research Funds for the Central Universities for financial support. The authors thank the Research Center of Analysis and Test of East China University of Science and Technology for the help on the characterization.

语种：英文

外文关键词：Cycloaddition - Regioselectivity - Aromatic compounds

摘要：Sulfolenopyrrole-based normal and N-confused phlorins have been constructed to address the seldom touched phlorin functionalization and simultaneously explore the effect of the pyrrole linkage modes (alpha alpha, alpha beta) on the [4 + 2] cycloaddition reaction. The common sulfolenophlorin 1 contains two sulfoleno-pyrroles with the same reactivity upon tautomerization and undergoes stepwise [4 + 2]-cycloaddition with fullerene to furnish monoadduct 1-C60 and bisadduct 1-2C60 with a total yield up to 76%. By contrast, the presence of the confused pyrrole in 2 fixes the Jr-system owing to the low tendency to tautomerize and enables the two sulfolenopyrroles to exhibit in different fashions (i.e., normal NH-type and imino-type). Notably, under milder conditions (120 degrees C), the monofullerenoadduct 2-C60 forms rapidly and has been isolated from the [4 + 2] cycloaddition reaction of 2 and fullerene as the predominant fraction, accompanied by a trace amount of bisadduct 2-2C60. Raising the temperature to 140 degrees C did not improve the yield of 2-2C60. The structural analysis of 2-C60 indicates the attachment of fullerene at the iminopyrrole part. The high regioselectivity in the [4 + 2] cycloaddition of the imino-type sulfolenopyrrole unit has been rationalized thermodynamically by the DFT calculation on the relative energy of the two diene intermediates.