# Highly Selective Catalytic Reactions of Alkenes and Alkynes Relevant to Medicinal and Process Chemistry

> **NIH NIH R35** · OHIO STATE UNIVERSITY · 2022 · $79,673

## Abstract

Project Summary/Abstract
 Discovery of fundamentally new catalytic reactions, especially enantioselective ones, showing
high turnover frequencies (i.e., substrate/ catalyst/unit time), that use readily available precursors,
will have a significant impact on medicinal and process chemistry. Through an approach that relies
heavily on mechanistic insights and attendant ligand designs, we aim to discover new
enantioselective reactions of alkenes and alkynes. For example, use of low-valent chiral (L*)cobalt
complexes has enabled heterodimerization between a broad range of 1,3-dienes, and, ethylene and
alkyl acrylates, which are feedstock materials. The products of these reactions are synthetically
valuable chiral 1,4-skipped dienes (produced in >90% yield and ee) which can be turned into
pharmaceutically relevant classes of compounds. Examples cited include anti-microbial and anti-
tumor and antifungal agents, GABA analogs, and metalloproteinase inhibitors. On-going
mechanistic studies strongly suggest the intermediacy of a cationic [(P~P)Co(L)]+X– species in these
exceptionally selective C-C bond-forming reactions that proceed under ambient conditions. Most
remarkably, we recently (2020/2021) found that the chiral cationic Co(I) complexes with custom-
designed ligands catalyze enantioselective [2+2]-additions of alkynes and vinyl-X derivatives,
opening, arguably, the best route to enantiopure 3-substituted cyclobutenes, potential precursors of
many other valuable compounds. In sharp contrast to 1,3-dienes, 1,3-enynes form, initially,
vinylcyclobutenes and then, in a tandem fashion, highly functionalized cyclobutanes with an all-
carbon quaternary centers. Such reactions are highly efficient and uncommon. Preliminary results
also indicate that chiral cationic Co(I)-complexes catalyze at least 4 other types of enantioselective
reactions (hydroboration, hydroacylation and hydrosilylation of prochiral 1,3-dienes, and,
cyclizaion/hydrovinylation of 1,6-enynes). We plan to explore how some of the combinations of
reactions can be run in tandem, in attempts to exploit the full potential of the new cobalt chemistry in
organic syntheis. Historically some of the reactions we work on had been carried out using precious
metals (Rh, Ir, Pd). We expect, when fully devloped, cobalt (which is up to 200 time cheaper than
Rh for example), will be able to catalyze some of these basic reactions. Rapid assays of selectivity
(-chemo-, regio- and enantioselectivities) are essential for the success of these projects and HPLC is
one of the most critical instruments we use. Through this submission we request funds for
replacement of an aging instrument (now more than 20 years old) that has been declared obsolete
by the manufacturer, thus becoming increasingly difficult to service and maintain.

## Key facts

- **NIH application ID:** 10581995
- **Project number:** 3R35GM139545-02S1
- **Recipient organization:** OHIO STATE UNIVERSITY
- **Principal Investigator:** T V RAJANBABU
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $79,673
- **Award type:** 3
- **Project period:** 2021-01-01 → 2025-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10581995

## Citation

> US National Institutes of Health, RePORTER application 10581995, Highly Selective Catalytic Reactions of Alkenes and Alkynes Relevant to Medicinal and Process Chemistry (3R35GM139545-02S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10581995. Licensed CC0.

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