National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei 11221, Taiwan, Republic of China.
Department of Chemistry, National Taiwan Normal University, Taipei 10610, Taiwan, Republic of China.
Chem Commun (Camb). 2021 Nov 16;57(91):12045-12057. doi: 10.1039/d1cc04397h.
Palladium-catalyzed and ligand-enabled C-H functionalization methods have emerged as a powerful approach for the preparation of therapeutically important motifs and complex natural products. Olefins, owing to their natural abundance, have been extensively employed for the formation of C-C and C-X bonds and the generation of various heterocycles. Traditionally, activated as well as starting materials with preinstalled functional groups, and also halide substrates under transition metal catalysis, have been employed for olefin difunctionalization. However, strategies for employing unactivated C-H bond functionalization to achieve alkene difunctionalization have rarely been explored. A possible solution to this challenge is the application of bulky ligands which enhances the reductive elimination pathway and inhibits β-hydride elimination to selectively yield difunctionalized alkene products. This feature article summarizes the utilization of unreactive C-H bonds in the Pd-catalyzed and ligand-enabled difunctionalization of alkenes.
钯催化和配体辅助的 C-H 功能化方法已经成为制备治疗上重要的基序和复杂天然产物的有力方法。由于其丰富的资源，烯烃已被广泛用于形成 C-C 和 C-X 键以及生成各种杂环。传统上，已活化的以及带有预安装官能团的起始材料，以及在过渡金属催化下的卤化物底物，都被用于烯烃的双官能化。然而，利用未活化的 C-H 键官能化来实现烯烃的双官能化的策略很少被探索。解决这一挑战的一个可能方法是应用大位阻配体，这可以增强还原消除途径并抑制β-氢消除，从而选择性地生成双官能化的烯烃产物。本文总结了钯催化和配体辅助的烯烃双官能化中未反应的 C-H 键的利用。
