# Visible Light-Enabled Synthesis of Heterocycles through Energy Transfer

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2021 · $305,552

## Abstract

Project Summary/Abstract
Azetidines, azetines, and oxetanes are four-membered heterocycles that exhibit desirable pharmacokinetic
effects and represent important building blocks in current medicinal chemistry. Cycloaddition reactions
between alkenes and imines or carbonyls, also referred to as (aza) Paternò-Büchi reactions, represent the
most direct synthetic approach to access these compounds, however the current utility of these
transformations is highly restricted due to the stringent requirement of UV-light and competing reaction paths
accessible upon photochemical excitation. Thus, the ability to incorporate functionalized azetidines, azetines,
and oxetanes into pharmaceutical lead structures is currently severely limited due to a lack of efficient synthetic
methods. To date, no visible light-based platform of general synthetic utility for cycloadditions between alkenes
and imines or carbonyls exists. The objective of the proposed research program is to identify and develop
chemical strategies that enable efficient cycloadditions between these functional groups to access azetidines,
azetines, and oxetanes based on energy transfer catalysis facilitated by visible light.
These new synthetic methods will provide general and modular protocols for the synthesis of a large variety of
heterocyclic motifs that are highly desirable in current medicinal chemistry. Additionally, the strategies
described will enable cycloaddition reactions between alkenes and imines or carbonyls under mild reaction
conditions with high functional group tolerance as they forego the requirement of UV-light. The utility of the
accessible 4-membered heterocycles as building blocks will be demonstrated in secondary modifications and
by enabling the synthesis of biologically active target structures from commercially available starting materials.
The compounds prepared within this research program will be incorporated into the compound library
maintained by the Center for Chemical Genomics (CCG) at the University of Michigan and become part of
high-throughput screening (HTS) approaches for biological research and new drug discovery projects.
In summary, the research described will enable general, catalytic strategies for aza Paternò-Büchi and
Paternò-Büchi reactions relying on energy transfer upon excitation with visible light. These new
transformations represent desirable synthetic tools that will enable direct access to functionalized azetidines,
azetines, and oxetanes, and are expected to have broad implications in the area of medicinal chemistry.

## Key facts

- **NIH application ID:** 10185529
- **Project number:** 1R01GM141340-01
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** Corinna Stefanie Schindler
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $305,552
- **Award type:** 1
- **Project period:** 2021-04-01 → 2025-02-21

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10185529

## Citation

> US National Institutes of Health, RePORTER application 10185529, Visible Light-Enabled Synthesis of Heterocycles through Energy Transfer (1R01GM141340-01). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10185529. Licensed CC0.

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