| 研究実績の概要 |
Tertiary anilines which bearing allylic units are essential structural skeletons found in many fluorescent dyes, organic functional materials, pharmaceuticals and natural products. In principle, the catalytic benzylic C－H addition of 2-methyl tertiary anilines to internal alkynes is the most atom-efficient process for the synthesis of allylated tertiary anilines. However, the transition metal catalyzed benzylic C－H addition to internal alkynes is highly challenging and the reports in this area are rare which limited to special substrates, such as 8-methylquinolines. Therefore, the exploration of novel catalysts to realize the benzylic alkenylation of 2-methyl tertiary anilines is still in great demand.
Over the last year, we have developed the stereo- and reigioslective benzylic C－H addition of 2-methyl anilines to internal alkynes by employing a scandium complex for the first time. Both symmetrical and unsymmetrical internal alkynes were suitable in this reaction system and the desired trisubstituted alkene products could be achieved in good yields with high stereo- and regioselectivity. This work represents the first example of rare-earth metal catalyzed alkenylation reaction of benzylic C－H bonds with internal alkynes. Overall, we wish that this report will enrich the method of catalytic C－H bond functionalization and further enable the exploration of new catalytic system.
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