In this manuscript, Maji and co-workers developed a branched selective allylation strategy to access C2-indolyl-all-carbon quaternary centers using allylboronic acids. Under mild conditions, this strategy has broad functional group tolerance, leaving the C3 position of the indole free and providing potential for further synthesis. They also used DFT to corroborate mechanistic pathways, and showed the potential for further application in the field of total synthesis like (±)-mersicarpine alkaloid. Based on the novelty and quality of this work and the requirements of Chem. Sci., this article is suitable for publication after some revisions.

1. It will be better to synthesize the target product from unsubstituted indole in one-pot if possible. And when 3-bromoindole or 3-iodoindole was used as the substrate, could the product 1aa also be obtained?

2. Could indoles with -OH group react with allylboronic acids?

3. In mechanism hypothesis, the author mentioned the process of N→B coordination. And I was curious about the changes of 1H NMR and 11B NMR of indoles when allylboronic acids was added.

4. For the convenience of readers, it will be better to add subheading summaries to every group of references. Meanwhile, related works on the (reverse-)prenylation of indoles or other heterocycles should be cited, such as Angew. Chem. Int. Ed. 2011, 50, 1402; Angew. Chem. Int. Ed. 2019, 58, 5438; Chin. J. Catal. 2021, 42, 1593; Angew. Chem. Int. Ed. 2021, 60, 8321.

5. There are several errors in the manuscript and should be checked carefully. For example,
   a) “aReaction Conditions” in Table 1 should be “aReaction conditions”.
   b) There should be a “.” after the legend “Scheme 2”.
   c) “&” in Scheme 1c should be “X”.

The authors have addressed all concerns and I recommend publication.