钌催化剂使具有挑战性的仲烷基卤化物的芳烃上的 CH 键官能化成为可能。特别是,钌 (II) 双羧酸配合物被证明是直接烷基化成功的关键,具有出色的不寻常的间位选择性。直接烷基化发生在温和的反应条件下,具有足够的范围和可耐受的有价值的官能团。进行了详细的机理研究,包括各种竞争实验以及与同位素标记底物的反应。这些研究为最初的可逆环金属化提供了强有力的支持。环钌化从而活化芳烃,用于随后用仲烷基卤化物进行远程亲电型取代。
Regiodivergent C−H and Decarboxylative C−C Alkylation by Ruthenium Catalysis:
<i>ortho</i>
versus
<i>meta</i>
Position‐Selectivity
作者:Korkit Korvorapun、Marc Moselage、Julia Struwe、Torben Rogge、Antonis M. Messinis、Lutz Ackermann
DOI:10.1002/anie.202007144
日期:2020.10.12
Ruthenium(II)biscarboxylate complexes enabled the selectivealkylation of C−H and C−C bonds at the ortho‐ or meta‐position. ortho‐C−HAlkylations were achieved with 4‐, 5‐ as well as 6‐membered halocycloalkanes. Furthermore, the judicious choice of the directing group allowed for a full control of ortho‐/meta‐selectivities. Detailed mechanistic studies by experiment and computation were performed and