摘要
选择性还原α,β-不饱和酮中C=C键是有机化学中极具潜力且最有挑战性的官能团转化之一.本文以空气中稳定且极少量的N-杂环卡宾银配合物为催化剂、苯硅烷为还原剂,在水相且温和条件下,以较高的收率实现了α,β-不饱和酮化合物中双键的选择性还原,该体系可以兼容氟、氯、溴、三氟甲基、氨甲基、氰基及酯基等官能团,具有工业应用的潜质, TON值高达11250.该方法可用于药物分子的合成,后处理操作简单,避免了氢气及高压釜设备,为酮类的制备提供了新的思路和方法.初步机理研究表明,原位生成的银氢中间体为活性物种,随后对双键的加成是实现转化的关键,后经水解得到双键还原产物.
The selective reduction of C=C bond in α,β-unsaturated ketones is one of the highly potent and challenging functional group transformations in organic chemistry. Therefore, the investigation of a simple and efficient new reductive system for the chemoselective reduction of α,β-unsaturated ketones is highly desirable. Herein, we presented a method for the homogeneous hydrogenation of C=C bond in the α,β-unsaturated carbonyl compound to produce ketone using low catalyst loading and air-stable silver N-heterocyclic carbene complexes as the catalyst and PhSiH_(3)as the source of hydrogen. A wide range of α,β-unsaturated ketones, featuring diverse functional groups, were selectively transformed into their corresponding ketones with moderate yields. This process can be readily scaled up and exhibits compatibility with various sensitive functional groups, including fluorine, chlorine, bromine, trifluoromethyl,aminomethyl, cyano and ester, with broad scope and particularly high turnover numbers(up to 11250). Notably, this catalytic methodology finds application in the synthesis of essential drug compounds. Meanwhile, the post-processing operation is simple and does not require hydrogen or autoclave equipment. Mechanistic investigations suggest that the in-situ-generated Ag-H species may serve as active intermediates. Intermediate is produced by the coordination of the C=C to AgH species, which is succeeded by the production of intermediate via the insertion of the C=C bonds into the Ag-H bond. The final product was obtained by hydrolysis intermediate in the presence of H_(2)O.
作者
焦红梅
周慧
鲁星
高媛媛
侯雪艳
张玉琦
韩波
Hongmei Jiao;Hui Zhou;Xing Lu;Yuanyuan Gao;Xueyan Hou;Yuqi Zhang;Bo Han(Laboratory of New Energy&New Functional Materials,Shaanxi Key Laboratory of Chemical Reaction Engineering,College of Chemistry and Chemical Engineering,Yan'an University,Yan'an 716000,China)
出处
《中国科学：化学》
CAS
CSCD
北大核心
2024年第7期1099-1106,共8页
SCIENTIA SINICA Chimica
基金
国家自然科学基金(编号:22061041)
陕西省重点研发计划(编号:2023-YBGY-430,2022GY-412)
榆林市产学研计划(编号:CXY-2022-185)
延安大学大学生创新创业训练计划(编号:D2022077)资助项目。
关键词
α
β-不饱酮
选择性
还原
水
N-杂环卡宾银配合物
a
β-unsaturated ketones
selectivity
reduction
water
silver N-heterocyclic carbene complexes
