Abstract
Divergent synthesis of medium-sized rings with controllable ring sizes represents a longstanding challenge in organic synthesis. Herein, we developed a transition-metal-catalyzed switchable divergent cycloaddition of para-quinone methides and vinylethylene carbonates by controlling the steric hindrance of substituent. Different from reported alkoxide-triggered annulations, this process undergoes a regiodivergent allylation of para-quinone methides followed by 1,6-addition reaction, providing a new route to selectively synthesize seven- to ten-membered nitrogen-containing heterocycles in high yields with excellent regioselectivities. This protocol features a broad substrate scope, wide functional group tolerance as well as operational simplicity. The reaction mechanism was investigated by conducting a series of control experiments as well as DFT calculations and the origins of the regioselectivities of the cycloaddition process were rationalized.
Original language | English (US) |
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Pages (from-to) | 4549-4558 |
Number of pages | 10 |
Journal | Chinese Chemical Letters |
Volume | 33 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2022 |
Keywords
- Divergent cycloaddition
- Medium-sized rings
- para-Quinone methides
- Regioselectivity
- Vinylethylene carbonates
ASJC Scopus subject areas
- General Chemistry