Research Overview

We are dealing with main group elements from group 13 to 16, at the border between organic, organometallic and inorganic chemistry, with some developments in the field of material science.We use the specific properties of main group elements, especially boron, silicon and phosphorus, to stabilize organic species, which are supposed to be only transient intermediates, such as carbenes, nitrenes, radicals and biradicals, 1,3-dipoles, anti-aromatic heterocycles...One of our major projects is the synthesis of stable localized singlet and triplet 1,3-diradicals using various combinations of group 13 to 15 main group elements. Diradicals are even-electron molecules that have one bond less than the number permitted by the standard rules of valence; the two remaining electrons occupy two orbitals that have the same or nearly the same energy and can have antiparallel (singlet state) or parallel spins (triplet state). These species, especially 1,3-diradicals, are even more ephemeral than monoradicals since their bifunctionality permits intermolecular as well as intramolecular coupling reactions. Before this work, the half lifetime at room temperature of the most persistent localized 1,3-diradical was only in the microsecond range. In 2002, we have isolated singlet diradical 1 that is indefinitely stable at room temperature. Aside from any fundamental curiosity, the availability of diradicals, which can be handled under standard laboratory conditions, should open the way to new developments in various fields. Of particular interest, catenation of singlet diradicals, via appropriate linkers, is predicted to lead to antiferromagnetic low-spin polymers, in which the half-filled electron bands would confer the capability for metallic conduction without doping. Triplet diradicals might serve as building blocks for the construction of conductively insulating high-spin polymers, with ferromagnetic properties. To address the former problem, the catenation of stable singlet diradicals, is being carried out.

Another important project is the synthesis of stable carbenes and their use as ligand for transition metal catalysts. The availability of catalysts to perform specific transformation is critical for both industry and academia. Over the years the success of homogeneous catalysis can be attributed largely to the development of a diverse range of ligand frameworks that have been used to tune the behavior of the various systems. This has led not only to highly active and selective catalysts, but also to the discovery of fundamentally new types of transition metal-mediated transformation. The efficiency of NHcarbene ligands in catalysis is now well established, and this is largely due to their strong s-donor property, which can be superior to that of the best phosphine donor ligands. Built on our long standing experience in stable carbene chemistry, we have a program directed towards the synthesis of brand new types of stable aminocarbene, which are predicted to donate even more electron density to metals than their NHcarbene counterparts. We also prepare typical transition metal catalysts, in which one the “classical” ligands, including NHcarbenes, is replaced by our new carbenes, and their catalytic properties are tested. Since structure/function relationships in catalysis are often either obscure or not readily predictable, once an initial lead catalyst has been identified, incremental changes in the ligand set have to be undertaken in order to bring the desired activity to useful levels. Therefore, the synthetic routes are designed in such a way that many slightly different carbenes could be obtained starting from a single precursor. There is a demanding need for technology to produce chemical substances in a pure enantiomeric form. For this purpose, special emphasis is drawn to the preparation of stable chiral carbene ligands. With NHcarbene ligands the source of asymmetry can only be placed in d- or g-position of the metal. We focuss on the synthesis of carbenes allowing for locating the source of asymmetry in a position ß to the metal center; this should enable more effective chirality transfer. Among our new carbenes are the CAACs and the Cyclopropenylidenes.

Selected Publications 2009 - 2000

Non-Metal Mediated Fragmentation of P4. Isolation of P1 and P2 Bis-Carbene Adducts. OlivierBack, Gleen Kuchenbeiser, Bruno Donnadieu, Guy Bertrand*, Angew. Chem. Int. Ed. 2009, in press.

Synthesis and Ligand Properties of a Persistent All-Carbon Four-Membered Ring Allene. M. Melaimi, P. Parameswaran, B. Donnadieu, G. Frenking, G. Bertrand*, Angew. Chem. Int. Ed. 2009, 48, in press.

Synthesis of a Simplified Version of Stable Bulky and Rigid Cyclic (Alkyl)(amino)carbenes, and Catalytic Activity of the Ensuing Gold(I) Complex in the Three-Component Preparation of 1,2-Dihydroquinoline Derivatives. Zeng, Xiaoming; Frey, Guido D.; Kinjo, Rei; Donnadieu, Bruno; Bertrand, Guy*. Journal of the American Chemical Society, in press. in Press

Synthesis of Allenylidene Lithium and Silver Complexes, and Subsequent Transmetallation Reactions. M. Asay.; B. Donnadieu.; W. W. Schoeller.; G. Bertrand*. Angew. Chem. Int. Ed. 2009, 48, in press.

Are allenes with zwitterionic character still allenes? Of course! Lavallo, Vincent; Dyker, C. Adam; Donnadieu, Bruno; Bertrand, Guy*. Angewandte Chemie, International Edition (2009), 48(9), 1540-1542.

A Cationic Gold(I) Complex as a General Catalyst for the Intermolecular Hydroamination of Alkynes: Application to the One-Pot Synthesis of Allenes from Two Alkynes and a Sacrificial Amine Xiaoming Zeng.; Guido D. Frey.; Shazia Kousar.; Guy Bertrand*. Chemistry - A European Journal, Vol 15, Issue 13, 2009, 3056-3060.

Response C. A. Dyker.; V. Lavallo.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 2009, 48

Isolation of Bicyclopropenylidenes, Derivatives of the Smallest Member of the Fulvalene Family R. Kinjo.; Y. Ishida.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 2009, 48, 517-520.

Response C. A. Dyker.; V. Lavallo.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 2009, 48

Isolation of Bicyclopropenylidenes, Derivatives of the Smallest Member of the Fulvalene Family R. Kinjo.; Y. Ishida.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 2009, 48

Soluble Allotropes of Main-Group Elements. C. Adam Dyker and Guy Bertrand*. Science "Perspectives" . 22 August (2008), 1050-1051.

Pd-Oxygen and Pd-Arene Interactions from Biaryl-Aminocarbenes: Similarities and Differences with Biaryl-Phosphanes J. Vignolle.; H. Gornitzka.; B. Donnadieu.; D. Bourissou.; G. Bertrand*. Angew. Chem. Int. Ed. (2008) , 47, 2271-2274

Soluble Allotropes of Main-Group Elements. C. Adam Dyker and Guy Bertrand*. Science "Perspectives" . 22 August (2008), 1050-1051.

Synthesis of a Strongly Bent Acyclic Allene (A "Carbodicarbene"): A Novel Type of Strong Donor Ligand C. A. Dyker.; V. Lavallo.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. (2008) , 47, 1 - 5

Tuning the nucleophilicity in cyclopropenylidenes. Schoeller, Wolfgang W.; Frey, Guido D.; G. Bertrand*. Chemistry--A European Journal (2008), 14(15), 4711-4718.

Homogeneous Catalytic Hydroamination of Alkynes and Allenes with Ammonia. Vincent Lavallo.; Frey, Guido D.; Bruno Donnadieu.; Michelle Soleilhavoup.; G. Bertrand*. Angew. Chem. Int. Ed. (2008) , 47, 5224-5228.

Kinetic Selectivity of Olefin Metathesis Catalysts Bearing Cyclic (Alkyl)(Amino)Carbenes. Anderson;. Donde R.; Ung, Thay.; Mkrtumyan Garik.; G. Bertrand*.; Grubbs* Robert H.; Schrodi, Yann. Organometallics (2008), 27(4), 563-566

Carbene Activation of P4 and Subsequent Derivatization J. D. Masuda.; W. W. Schoeller.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 46, 7052-7055 (2007)

Allene Formation by Gold Catalyzed Cross-Coupling of Masked Carbenes and Vinylidenes V. Lavallo.; G. D. Frey.; S. Kouzar.; B. Donnadieu.; G. Bertrand*. Proc. Natl. Acad. Sci. USA, 104, 13569-13573 (2007)

Recently Reported Crystalline Isothiazole Carbenes: Myth or Reality? A. Dehope.; V. Lavallo.; B. Donnadieu.; W. W. Schoeller.; G. Bertrand*. Angew. Chem. Int. Ed. 46, 6922-6925 (2007)

Synthesis and Reactivity of Olefin Metathesis Catalysts Bearing Cyclic (Alkyl)(Amino)Carbenes D. R. Anderson.; V. Lavallo.; D. J. O'Leary.; G. Bertrand*.; R. H. Grubbs*. Angew. Chem. Int. Ed. 46, 7262-7265 (2007)

Thermal Valence Isomerization of 2,3-Diborata-1,4-diphosphoniabuta-1,3-dienes to Bicyclo[1.1.0]butanes and Cyclobutane-1,3-diyls J. B. Bourg.; A. Rodriguez.; D. Scheschkewitz.; H. Gornitzka.; D. Bourissou.' G. Bertrand*. Angew. Chem. Int. Ed. 46, 5741-5745 (2007)

Facile Splitting of Hydrogen and Ammonia by Nucleophilic Activation at a Single Carbon Center, G.D. Frey.; V. Lavallo.; B. Donnadieu.; W.W. Schoeller.; G. Bertrand*. Science 316, 439-441 (2007)

Cyclopropenylidenes: From Interstellar Space to an isolated Derivative in the Laboratory, V. Lavallo.; Y. Canac.; B. Donnadieu.; W. W. Schoeller.; G. Bertrand*. Science. 312, 722-724 (2006)

Stable Four pi-Electron, Four-Membered Heterocyclic Cations and Carbenes Y. Ishida.; B. Donnadieu.; G. Bertrand*. P.N.A.S. 103, 13585-15588 (2006)

CO Fixation to Stable Acyclic and Cyclic Alkyl Amino Carbenes: Stable Amino Ketenes with a Small HOMO-LUMO Gap V. Lavallo.; Y. Canac.; B. Donnadieu.; W. W. Schoeller.; G. Bertrand*. Angew. Chem. Int. Ed. 45, 3488-3491 (2006)

Isolation of Cyclopropenylidene Lithium Adducts: The Weiss-Yoshida Reagent V. Lavallo.; Y. Ishida.; D. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 45, 6652-6655 (2006)

Cyclic C-Amino Phosphorus Ylides as a Source of Bidentate Heteroditopic Ligands (Phosphine / Aminocarbene) for Transition Metals J. Vignolle.; B. Donnadieu.; D. Bourissou.; M. Soleilhavoup.; G. Bertrand*. J. Am. Chem. Soc. 128, 14810 - 14811 (2006)

Synthesis of Transient and Stable C-Amino Phosphorus Ylides and their Fragmentation into Transient and Stable Carbenes Y. Canac.; S. Conejero.; M. Soleilhavoup.; B. Donnadieu.; G. Bertrand* . J. Am. Chem. Soc. 128, 459-464 (2006)

Isolation of Elusive Low Coordinate Transition Metal Complexes Thanks to a Rigid Cyclic (Alkyl)(Amino)Carbene Ligand V. Lavallo.; Y. Canac.; A. Dehope.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 44, 7236-7239 (2005)

Stable Cyclic (Alkyl)(Amino)Carbenes as Rigid or Flexible, Bulky, Electron-Rich Ligands for Transition Metal Catalysts: a Quaternary Carbon Makes the Difference V. Lavallo.; Y. Canac.; C. Praesang.; B. Donnadieu.; G. Bertrand*. Angew. Chem. Int. Ed. 44, 5705-5709 (2005)

A Stable P-Heterocyclic Carbenes D. Martin.; A. Baceiredo.; H. Gornitzka.; W. W. Schoeller.; G. Bertrand*. Angew. Chem. Int. Ed. 44, 1700-1703 (2005)

Stable Planar Six-p-Electron Six-Membered N-Heterocyclic Carbenes with Tunable Electronic Properties C. Praesang.; B. Donnadieu.; G. Bertrand*. J. Am. Chem. Soc. 127, 10182-10183 (2005)

Persistent (Amino)(Silyl)Carbenes Y. Canac.; S. Conejero.; B. Donnadieu.; W. W. Schoeller.; G. Bertrand*. J. Am. Chem. Soc. 127, 7312-7313 (2005)

The Modest Undressing of a Silicon Center G. Bertrand*. Science (Perspective) 305, 783-785 (2004)

Carbene’s synthesis via Substitution Reactions at a Carbene Center N. Merceron-Saffon.; A. Baceiredo.; H. Gornitzka.; G. Bertrand*. Science 301, 1223-1225 (2003)

Singlet diradicals: from transition states to crystalline compounds D. Scheschkewitz.; H. Amii.; H. Gornitzka.; W.W. Schoeller.; D. Bourissou.; G. Bertrand*. Science, 295, 1880-1881 (2002)

(Amino)(aryl)carbenes : stable singlet carbenes featuring a spectator substituent S. Sole.; H. Gornitzka.; W.W. Schoeller.; D. Bourissou.; G. Bertrand*. Science, 292, 1901-1903 (2001)

A cyclic carbanionic valence isomer of a carbocation : diphosphino analogs of diaminocarbocations T. Kato.; H. Gornitzka.; A. Baceiredo.; W.W. Schoeller.; G. Bertrand*. Science, 289, 754-756 (2000)

Stable versions of transient push-pull carbenes : extending lifetimes from nanoseconds to weeks C. Buron.; H. Gornitzka.; V. Romanenko.; G. Bertrand*. Science, 288, 834-836 (2000)

Recent Honors and Awards

Novartis Lectureship at the Scripps Research Institute, La Jolla, 2009-2010

Sir Ronald Nyholm Lectureship 2009/2010

East Cost Lecturer (Scotland), 2007

Elected Fellow of the AAAS, 2006

Elected Member of the French Academy of Sciences, 2004

Taiwan National Research Council Distinguished Lecturer, 2003

Elected at the European Academy of Sciences, 2003

Elected at the Academia Europaea, 2002

Elected at the French Academy of Technology, 2000

Japanese Society for Promotion of Science Award, 1999

Médaille d'Argent du CNRS, 1998

Kharasch Lecturer, University of Chicago, 1998

Elected at the French Academy of Sciences (Membre Correspondant), 1996

French-German Humboldt Award, 1994

International Council on Main Group Chemistry Award, 1993