Catalyst-Controlled Divergent C-H Functionalization of Unsymmetrical 2-Aryl Cyclic 1,3-Dicarbonyl Compounds with Alkynes and Alkenes
Catalyst-Controlled Divergent C-H Functionalization of Unsymmetrical 2-Aryl Cyclic 1,3-Dicarbonyl Compounds with Alkynes and Alkenes
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DOI：
10.1021/ja404867k
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发表时间：
2013-07-24
影响因子：
15
通讯作者：
Lam, Hon Wai
中科院分区：
文献类型：
--
作者：
Dooley, Johnathon D.;Chidipudi, Suresh Reddy;Lam, Hon Wai
实现含有几种不同类型的反应性C-H键的底物的位点选择性可切换C-H官能化是一个有吸引力的目标，以使得能够从相同的起始材料产生不同的产物。在这里，我们证明了发散C-H官能化的不对称2-芳基环状1，3-二羰基化合物，包含两个不同的，不相邻的网站初始C-H官能化，其中通过催化剂控制实现产品的选择性。通过使用钯N-杂环碳烯络合物作为预催化剂，这些底物与炔进行氧化成环以专门提供螺茚。相比之下，基于铼的催化剂体系得到苯并吡喃作为主要产物。还提供了相同底物的不同的氧化C-H烯基化的实例。
Achieving site-selective, switchable C-H functionalizations of substrates that contain several different types of reactive C H bonds is an attractive objective to enable the generation of different products from the same starting materials. Herein, we demonstrate the divergent C-H functionalization of unsymmetrical 2-aryl cyclic 1,3-dicarbonyl compounds that contain two distinct, nonadjacent sites for initial C-H functionalization, where product selectivity is achieved through catalyst control. By use of a palladium N-heterocyclic carbene complex as the precatalyst, these substrates undergo oxidative annulation with alkynes to provide spiroindenes exclusively. In contrast, a ruthenium-based catalyst system gives benzopyrans as the major products. Examples of divergent, oxidative C-H alkenylations of the same substrates are also provided.