# Stereoselective Photochemistry for the Synthesis of Bioactive Molecules

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 2022 · $39,770

## Abstract

Stereoselective chemical reactions have transformed human medicine by providing access to chemical
tools to study biological systems and pharmaceutical drugs to treat disease. Although several methods exist for
the synthesis of biologically valuable chiral molecules, there is great potential for discovering conceptually
novel strategies in catalysis for the stereoselective synthesis of molecules not easily accessed by known
methods. We are particularly interested in developing catalytic stereoselective photochemical reactions that
are useful for the generation of biologically valuable chiral products but have been traditionally thought to be
unamenable to asymmetric catalysis. These innovative strategies will complement the current known methods
in asymmetric photochemistry. We propose to develop a general platform for enantioselective a-alkylations of
carbonyl compounds with pyridinium salts and a new approach to enantioselective C–H alkylations of imines.
 Our long-term goals for this research program include the discovery of general and robust strategies for the
catalytic conversion of simple starting materials into structurally complex and biologically active small
molecules. We also anticipate that these methods will challenge established opinions of chemical reactivity that
have been held about certain classes of photochemical reactions for years. By utilizing sustainable sources of
energy (such as low energy visible light), the new strategies in stereoselective photochemistry discovered by
our laboratory will provide an environmentally benign alternative to access medicinally relevant chiral
enantioenriched molecules that are not easily synthesized by other methods.
 In Specific Aim 1, we propose to develop a general platform for the catalytic enantioselective a-alkylation of
carbonyl compounds with pyridinium salts derived from readily available primary amines as alkylating reagents.
This specific aim is guided by the hypothesis that electron poor pyridinium salts can form ground-state charge-
transfer complexes with catalytically generated electron rich chiral enolate equivalents. These complexes can
then undergo stereoselective couplings in the presence of low energy visible light. In the long-term, we will
develop a general platform for the photochemical catalytic enantioselective a-alkylation of carbonyl compounds
with pyridinium salts based on several modes of asymmetric catalysis.
 In Specific Aim 2, we propose to develop a general platform for the synthesis of enantioenriched amines
via the photochemical C–H alkylation of acyclic imines. This specific aim is guided by the hypothesis that in the
presence of visible light, a sub-stoichiometric amount of chiral Lewis acid can furnish enantioenriched amine
products with high stereoselectivity by accelerating the coupling event between an imine substrate and various
hydrocarbon alkylating agents. In the long-term, we will develop a general approach for the photochemical
enantioselective...

## Key facts

- **NIH application ID:** 10486355
- **Project number:** 3R01GM102604-10S1
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **Principal Investigator:** UTTAM Krishan TAMBAR
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $39,770
- **Award type:** 3
- **Project period:** 2012-09-01 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10486355

## Citation

> US National Institutes of Health, RePORTER application 10486355, Stereoselective Photochemistry for the Synthesis of Bioactive Molecules (3R01GM102604-10S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10486355. Licensed CC0.

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