A computational triage approach to the synthesis of novel difluorocyclopentenes and fluorinated cycloheptadienes using thermal rearrangements
作者:David Orr、Jonathan M. Percy、Zoë A. Harrison
DOI:10.1039/c6sc01289b
日期:——
ability to undergo vinyl cyclopropane rearrangements (VCPR). Groups which effectively stabilised radicals, specifically heteroarenes, were found to result in the lowest energy barriers. Ten novel precursors were synthesised to test the accuracy of computational predictions; the most reactive species which contained heteroarenes underwent thermal rearrangements at room temperature to afford novel d
电子结构计算已用于有效分类取代基对二氟化乙烯基环丙烷前体的影响及其进行乙烯基环丙烷重排 (VCPR) 的能力。发现有效稳定自由基,特别是杂芳烃的基团产生最低的能垒。合成了十种新的前体来测试计算预测的准确性;含有杂芳烃的最具反应性的物质在室温下经历热重排,分别通过竞争的 VCPR 和 [3,3]-重排途径提供新的二氟环戊烯和氟化苯并环庚二烯。更可控的 3-(1'(2'2'-difluoro-3'-benzo[ d ][1,3]dioxol-5-yl)cyclopropyl) 丙烯酸乙酯重排 ( 22) 允许同时监测这些竞争途径,并确定两种反应的活化能;E a(VCPR) = (23.4 ± 0.2) kcal mol -1和E a([3,3]) = (24.9 ± 0.3) kcal mol -1. 将我们计算出的活化能与这些参数进行比较表明,没有一种方法能最准确地预测势垒高度。(U)M05-2X/6-31+G*