PIPages
Labs

Robert R Knowles

Princeton University, NJ·Chemistry

Most chemical reactions slide toward the most stable product, the way a ball rolls downhill. That limits which molecules chemists can make.

Fields

Chemistry

Topics

organic synthesis

synthetic methodology

photocatalysis

Grants
1 known grant, through Dec 2029

What they work on

  1. Develop light-driven deracemization of ketones and asymmetric contra-thermodynamic olefin isomerization, using excited-state redox catalysis to give product mixtures not reachable by ordinary heat-driven reactions.
  2. Use proton-coupled electron transfer (PCET, moving a proton and electron together) to cleave carbon–carbon bonds in amino alcohols and cyclic 1,2-diols, forming ring-expanded amines, lactams, cyclic ethers and lactones.
  3. Create a general PCET method for anti-Markovnikov hydroamination, adding sulfonamide nitrogen groups across unactivated carbon–carbon double bonds with a wider range of amine partners.
  4. Develop PCET reactions of hydrazones, including room-temperature Wolff–Kishner-type deoxygenations and ring contraction of pyrazolines into cyclopropanes, and expand phenol substitution through phenoxyl radicals.

More about the research

This research uses light to push reactions "uphill", producing mixtures of products that ordinary heat-driven reactions cannot give. The key idea is excited-state redox chemistry: a catalyst absorbs light and then moves electrons to or from the starting molecule, so the starting molecule itself never needs to absorb light.

Why it matters

Many drugs and biological probe molecules are built from ring-shaped amines, small rings and single-handed structures. New light-driven and PCET reactions could give chemists in drug discovery and pharmaceutical manufacturing simpler ways to make these structures, including products that standard reactions cannot reach.

Known grants

From NIH and NSF research grants. Labs often have other funding we can't see.

New Synthetic Methods Enabled by Excited-State Redox Chemistry

NIH · Jan 2020 – Dec 2029

Closest labs

Ramesh Giri

Pennsylvania State University, PA·Chemistry

Develop transition-metal-catalyzed difunctionalization of alkenes bearing simple functional groups, using a dual ligand system of electron-deficient alkenes and organic nitriles to stabilize intermediates and promote C(sp3)–C(sp3) bond formation.

Tomislav Rovis

Columbia University, NY·Chemistry

Develop reactions that build nitrogen-containing rings (heterocycles) directly from simple feedstocks such as alkenes and alkanes, forming carbon–carbon and carbon–nitrogen bonds in one step without later manipulation.

Michel Gagne

University of North Carolina at Chapel Hill, NC·Chemistry

Develop site-selective and functional group-directed C-H functionalization reactions, which convert specific carbon-hydrogen bonds into new groups, using light-activated organic photoredox catalysts.

The school

Princeton University: 26 labs on PI Pages, $559M a year on research, 403 research doctorates a year.

More about Princeton University

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