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Warmuth, Ralf

Position: 
Associate Professor

Ralf Warmuth Phone: 848-445-8432
E-mail: E-mail
FAX: 732-445-5312
Lab: 732-445-3226
Office: Wright Rieman Labs 380/392
Mail: Chemistry & Chemical Biology, 610 Taylor Road, Piscataway, NJ 08854
Education Links
  • 1989 Diploma, Universität zu Köln, Germany
  • 1992 Ph. D., Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
  • 1992-94 Postdoctoral researcher, University of Nottingham, U.K.
  • 1994-97 Feodor Lynen fellow, University of California at Los Angeles

Research Summary

Host-Guest Chemistry; Supramolecular Chemistry; Design and Synthesis of Molecular Containers; Inner Phase Chemistry and Catalysis; Reactive Intermediates; Strained Hydrocarbons; De Novo Design of Helical Peptides; Conformationally Constrained Amino Acids; Peptide-based Ion-Channels; Photochemical Triggers for Protein Folding

Host-Guest isolation of reactive intermediates: 1,2,4,6-cycloheptatetraene

enantiomerization of 1,2,4,6-cycloheptatetraene (CHTE)The enantiomerization of 1,2,4,6-cycloheptatetraene (CHTE) in the inner phase of a chiral hemicarcerand. The enantiomerization of CHTE via the planar cycloheptatrienylidene (CHT) as the transition state is an important part of the phenylcarbene rearrangement. Recently, we generated CHTE photochemically in the inner phase of a chiral hemicarcerand, which prevented the dimerization of the highly strained guest. This allowed us to measure the exchange rate between the two diastereomeric CHTE hemicarceplexes (left and right structures) and to determine the enantiomerization barrier.

 

 

 

 

Host-Guest isolation of reactive intermediates: o-benzyne

o-benzyneThe photochemical generation of o-benzyne in the inner phase of a hemicarcerand (center). Photolysis of incarcerated benzocyclobutenedione yields o-benzyne and two molecules of CO, which escape the inner phase (bottom right bull eye). The surrounding hemicarcerand protected the highly strained o-benzyne from self-destruction, e.g. dimerization, and allowed us to characterize for the first time o-benzyne by liquid phase NMR spectroscopy. Partial 13C-NMR spectra of a fully 13C-labeled o-benzyne are shown in the bull eyes on the left side and in the upper right corner.

 

 

 

 

 

 

Conformationally constrained peptides

conformationally constrained lysineA conformationally constrained lysine induces a single alpha helical turn in a short peptide.

 

 

 

 

 

 


Publications

o-Benzyne: Strained Alkyne or a Cumulene?-NMR Characterization in a MolecularContainer. Ralf Warmuth, Angew. Chem. Int. Ed. Engl. 1997, 36, 1347-1350. pdf

First innermolecular Diels-Alder reaction of o-benzyne inside a molecular container compound. Ralf Warmuth, J. Chem. Soc., Chem. Commun., 1998, 59-60. pdf

The Inner Phase of Molecular Container Compounds as a Novel Reaction Environment.
Ralf Warmuth, J. Inclusion Phenomena and Molecular Recognition in Chemistry, 2000, 37, 1-38.

1,2,4,6-Cycloheptatetraene: Room temperature stabilization inside a hemicarcerand.
Ralf Warmuth and Melissa A. Marvel, Angew. Chem. Int. Ed. Engl., 2000, 39, 1117-1119. pdf

Inner Phase Stabilization of Reactive Intermediates. Ralf Warmuth, Eur. J. Org. Chem., 2001, 423-437. pdf

Chemistry and Properties of Cycloheptatetraene Inside a Hemicarcerand. Ralf Warmuth and Melissa A. Marvel, Chem. Eur. J., 2001, 7, 1209-1220. pdf

Recent Highlights in Hemicarcerand Chemistry. Ralf Warmuth and Juyoung Yoon, Accounts of Chemical Research, 2001, 34, 95-105. pdf

Enantioselective synthesis of benzocyclic alpha, alpha-dialkyl-amino acids: New insight into the solvent dependent stereoselectivity of the TMS-CN addition to phenylglycinol derived imines. Ralf Warmuth, Tamara E. Munsch, Robert A. Stalker, Bing Li and Alicia Beatty, Tetrahedron., 2001, 57, 6383-6397. pdf

The Enantiomerization Barrier of 5-Methylcyclohepta-1,2,4,6-tetraene. Ralf Warmuth, J. Am. Chem. Soc., 2001, 123, 6955-6956. pdf

Rate Acceleration Through Dispersion Interactions: Insight into the Effect of a Hemicarcerand on the Transition State of Inner Phase Diazirine Decompositions. Ralf Warmuth, Jean-Luc Kerdelhue, Sigifredo Sanchez Carrera, Kevin J. Langenwalter, and Neil Brown. Angew. Chem. Int. Ed. Engl., 2002, 41, 96-99. pdf

Asymmetric Synthesis of two new Conformationally Constrained Lysine Derivatives. Ralf Warmuth, Tamara E. Munsch, Robert A. Stalker, Jacquelyn D. Tran, Xiaoping Nie, Alicia Beatty, and Christer Aakeroy, Tetrahedron, 2002, 58, 4837-4849. pdf

Chiral recognition by hemicarcerand-like host in aqueous solution. Harmit Singh and Ralf Warmuth, Tetrahedron, 2002, 58, 1257-1264. pdf

Mapping the Potential Energy Surface of the Tolylcarbene Rearrangement in the Inner Phase of a Hemicarcerand. Jean-Luc Kerdelhue, Kevin J. Langenwalter, Ralf Warmuth, J. Am. Chem. Soc., 2003, 125, 973-986. pdf

Temperature dependence of the kinetic isotope effect and tunneling contribution in the innermolecular reaction of phenylcarbene inside a hemicarcerand. Carly Kemmis and Ralf Warmuth, J. Supramol. Chem. 2003, 253 - 267.

Through-shell alkyl lithium additions and borane reductions. Ralf Warmuth, Emily F. Maverick, Carolyn, B. Knobler and Donald J. Cram, J. Org. Chem., 2003, 68, 2077-2088. pdf

The room-temperature stabilization of bicyclo[2.2.2]oct-1-ene and bicyclo[3.2.1]oct-1-ene. Paul Roach and Ralf Warmuth, Angew. Chem. Int. Ed. Engl., 2003, 42, 3039-3042. pdf

The Phenylnitrene Rearrangement in the Inner Phase of a Hemicarcerand. Ralf Warmuth and Slawomir Makowiec, J. Am. Chem. Soc., 2005, 127, 1084-1085. pdf

Fluorophenoxycarbene inside a hemicarcerand: a bottled singlet carbene. Xuejun Liu, Gaosheng Chu, Robert A. Moss, Ronald R. Sauers, and Ralf Warmuth, Angew. Chem. Int. Ed. Engl., 2005, 44, 1994-1997. pdf

A ’Through-Shell’ Binding Isotope Effect. Yong Liu and Ralf Warmuth, Angew. Chem. Int. Ed. Engl., 2005, 44, 7107-7110. pdf

One-Pot 18 Component Synthesis of an Octahedral Nanocontainer Molecule. Xuejun Liu, Yong Liu, Gina Li, Ralf Warmuth, Angew. Chem. Int. Ed. Engl., 2006, 45, 901-904. pdf

Solvent Effects in Thermodynamically Controlled Multi-Component Nanocapsule Syntheses. Xuejun Liu and Ralf Warmuth, J. Am. Chem. Soc. 2006, 128, 14120 – 14127. pdf

Photochemical and Thermal Reactions of Intermediates in the Phenylnitrene. Rearrangement Inside a Hemicarcerand. Ralf Warmuth and Slawomir Makowiec, J. Am. Chem. Soc., 2007, 129, 1233-1241. pdf

A simple one-pot multi-component synthesis of an octahedral nanocontainer molecule. Xuejun Liu and Ralf Warmuth, Nature Protocols 2007, 2, 1288-1296. pdf

Isotope Effects as Probe of Constrictive and Intrinsic Binding in Hemicarceplexes. Yong Liu and Ralf Warmuth, Org. Lett. 2007, 9, 2883 – 2886. pdf

Multi-component Dynamic Covalent Assembly of a Rhombicuboctahedral Nanocapsule. Yong Liu, Xuejun Liu and Ralf Warmuth, Chemistry. A European Journal 2007, 13, 8953 – 8959. pdf

Multi-Component Synthesis of Tetracavitand Nanocapsules. Xuejun Liu, Yong Liu, and Ralf Warmuth, Supramolecular Chemistry 2008, 20, 41 - 50.

Edge-directed dynamic covalent synthesis of a chiral nanocube. Di Xu and Ralf Warmuth, J. Am. Chem. Soc., 2008, 130, 7520-7521. pdf

Water-soluble octahedral polyammonium nanocapsules: Synthesis and encapsulation studies. Xuejun Liu and Ralf Warmuth, Tetrahedron, 2009, 65, 7303-7310. pdf

Innermolecular Reactions of Fluorophenylcarbene Inside a Hemicarcerand. Zhifeng Lu, Robert A. Moss, Ronald R. Sauers, and Ralf Warmuth. Organic Letters, 2009, 11, 3866-3869. pdf

Reactions Inside Carcerands. Ralf Warmuth, in Molecular Encapsulation: Reactions in Constrained Systems, Udo H. Brinker, Jean-Luc Mieusset (Eds.), John Wiley, 2010, Chapter 9, 227-268.

Thermodynamically-controlled synthesis of a chiral tetra-cavitand nanocapsule and mechanism of enantiomerization. Junling Sun, James L. Bennett, Thomas J. Emge and Ralf Warmuth, J. Am. Chem. Soc., 2011, ASAP pdf

Templated dynamic cryptophane formation in water. Cécile Givelet, Junling Sun, Di Xu, Thomas J. Emge, Ashwini Dhokte and Ralf Warmuth. Chem. Commun., 2011, in press. DOI: 10.1039/c1cc10510h


Research Areas: 
Materials Chemistry
Research Areas: 
Organic Chemistry

Rutgers, The State University of New Jersey