Copper-Catalyzed Tunable Oxygenative Rearrangement of Tetrahydrocarbazoles.
Hai RenBing-Qing YangJun ShiWei WuBiaobiao JiangQin ChiPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2024)
Herein, we report a general copper-catalyzed method for the tunable oxygenative rearrangement of tetrahydrocarbazoles to cyclopentyl-bearing spiroindolin-2-ones and spiroindolin-3-ones. The method demonstrates excellent chemoselectivity, regioselectivity, and product control simply by using the H 2 O and O 2 as oxygen source, respectively. This open-flask method is safe and simple to operate, and no other chemical oxidants are required. Besides, inspired from the unique pathway of 1, 2-migration rearrangement, a highly controllable hydroxylation of indoles for the construction of C3a-hydroxyl iminium indolines was also developed. Mechanistic experiments suggest that a single-electron transfer-induced oxidation process is responsible for the tunable selectivity control.