Synthesis 2022; 54(04): 925-942
DOI: 10.1055/a-1480-3215
special topic
Cycloadditions – Established and Novel Trends – in Celebration of the 70th Anniversary of the Nobel Prize Awarded to Otto Diels and Kurt Alder

Highly Efficient Visible-Light-Driven [2+2] Cycloaddition of Maleimides to Alkenes and Alkynes for the Synthesis of 3-Aza­bicyclo[3.2.0]heptane-Fused Scaffolds

Jian He
,
Qiang Liu
We thank the National Natural Science Foundation of China for financial support (No. 21871123).


Abstract

A highly efficient [2+2] cycloaddition between maleimides and unsaturated moieties, utilizing a visible-light triplet sensitization mode, has been developed for the direct synthesis of multifunctional 3-azabicyclo[3.2.0]heptane derivatives. This reaction relies on selective activation of the maleimide functionality upon energy transfer from a new photosensitizer that outperforms diverse well-established photosensitizers. The strategy developed herein overcomes previous obstacles such as limited substrate scope and undesired reaction pathways under harsh UV irradiation.

Supporting Information



Publication History

Received: 18 March 2021

Accepted after revision: 12 April 2021

Accepted Manuscript online:
12 April 2021

Article published online:
12 May 2021

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