Distinct Palladium(II) Carbene Complexes Supported by Six-Membered 1,3-Disubstituted Permidin-2-ylidene, Six-Membered N-Heterocyclic Carbenes

The first synthesis, isolation, and characterization of permidin-2-ylidene complexes of Pd(II) is reported with entry resulting from either a direct reaction with isolable six-membered N-heterocyclic carbene or from the enetetramine, arising from dimerization of the carbene. Furthermore, a simplified method to prepare N,N′-disubstituted perimidinium bromide salts, precursors to 1,3-disubstituted perimidin-2-ylidene, was achieved using ammonium bromide as a source of weak acid. Through synthesis and nuclear magnetic resonance spectroscopic analysis of a carbene-phosphinidine adduct, an interrogation of the fundamental π-bonding ability of 1,3-diisopropylperimidin-2-ylidene revealed this interaction to be weak and of a similar order to unsaturated imidazol-2-ylidenes.

[1]  C. Mirkin,et al.  Palladium(II) Weak-Link Approach Complexes Bearing Hemilabile N-Heterocyclic Carbene-Thioether Ligands. , 2017, Inorganic chemistry.

[2]  Eduardo Peris,et al.  Smart N-Heterocyclic Carbene Ligands in Catalysis. , 2017, Chemical reviews.

[3]  Chenxi Ma,et al.  Ruthenium and osmium complexes of dihydroperimidine-based N-heterocyclic carbene pincer ligands. , 2015, Dalton transactions.

[4]  D. Stalke,et al.  Anagostic interactions under pressure: attractive or repulsive? , 2015, Angewandte Chemie.

[5]  G. Sheldrick.  Crystal structure refinement with SHELXL , 2015, Acta crystallographica. Section C, Structural chemistry.

[6]  O. Kazheva,et al.  Perimidin-2-ylidene rhodium(I) complexes; unexpected halogen exchange and catalytic activities in transfer hydrogenation reaction , 2014 .

[7]  H. Huynh,et al.  Bis(functionalized NHC) Palladium(II) Complexes via a Postmodification Approach , 2014 .

[8]  F. Glorius,et al.  An overview of N-heterocyclic carbenes , 2014, Nature.

[9]  C. Hättig,et al.  Bidentate cycloimidate palladium complexes with aliphatic and aromatic anagostic bonds. , 2014, Chemical communications.

[10]  Caitlin M. A. McQueen,et al.  Dihydroperimidine-Derived PNP Pincer Complexes as Intermediates en Route to N-Heterocyclic Carbene Pincer Complexes , 2014 .

[11]  C. Ganter,et al.  Converting a perimidine derivative to a cationic N-heterocyclic carbene , 2014 .

[12]  Antonio Martín,et al.  Synthesis, characterization, and computational study of complexes containing Pt···H hydrogen bonding interactions. , 2014, Inorganic chemistry.

[13]  A. Prokop,et al.  A chemical-biological evaluation of rhodium(I) N-heterocyclic carbene complexes as prospective anticancer drugs. , 2013, Chemistry.

[14]  K. Schaper,et al.  Determining the π-Acceptor Properties of N-Heterocyclic Carbenes by Measuring the 77Se NMR Chemical Shifts of Their Selenium Adducts , 2013 .

[15]  K. Mashima,et al.  Hemilabile N-xylyl-N'-methylperimidine carbene iridium complexes as catalysts for C-H activation and dehydrogenative silylation: dual role of N-xylyl moiety for ortho-C-H bond activation and reductive bond cleavage. , 2013, Journal of the American Chemical Society.

[16]  D. J. Nelson,et al.  Quantifying and understanding the electronic properties of N-heterocyclic carbenes. , 2013, Chemical Society reviews.

[17]  C. Ganter,et al.  Tuning the electronic properties of an N-heterocyclic carbene by charge and mesomeric effects. , 2013, Chemical communications.

[18]  W. Scherer,et al.  On the chemical shifts of agostic protons. , 2013, The journal of physical chemistry. A.

[19]  G. Bertrand,et al.  31P NMR chemical shifts of carbene-phosphinidene adducts as an indicator of the π-accepting properties of carbenes. , 2013, Angewandte Chemie.

[20]  Louis J. Farrugia,et al.  WinGX and ORTEP for Windows: an update , 2012 .

[21]  G. Bertrand,et al.  A cyclic diaminocarbene with a pyramidalized nitrogen atom: a stable N-heterocyclic carbene with enhanced electrophilicity. , 2012, Angewandte Chemie.

[22]  A. Comas‐Vives,et al.  How Important Is Backbonding in Metal Complexes Containing N‐Heterocyclic Carbenes? Structural and NBO Analysis , 2011 .

[23]  S. Bellemin‐Laponnaz,et al.  Synthetic routes to N-heterocyclic carbene precursors. , 2011, Chemical reviews.

[24]  G. Bertrand,et al.  Stable cyclic carbenes and related species beyond diaminocarbenes. , 2010, Angewandte Chemie.

[25]  F. Glorius,et al.  The measure of all rings--N-heterocyclic carbenes. , 2010, Angewandte Chemie.

[26]  H. Miyasaka,et al.  Carboxylate Ligand-Induced Intramolecular C−H Bond Activation of Iridium Complexes with N-Phenylperimidine-Based Carbene Ligands , 2010 .

[27]  W. Thiel,et al.  Steering the surprisingly modular pi-acceptor properties of N-heterocyclic carbenes: implications for gold catalysis. , 2010, Angewandte Chemie.

[28]  P. Hitchcock,et al.  Coordination of neutral, methylene bridged bis-guanidyls at palladium. , 2010, Dalton Transactions.

[29]  D. Gusev.  Electronic and Steric Parameters of 76 N-Heterocyclic Carbenes in Ni(CO)3(NHC) , 2009 .

[30]  C. Bielawski,et al.  An N,N'-diamidocarbene: studies in C-H insertion, reversible carbonylation, and transition-metal coordination chemistry. , 2009, Journal of the American Chemical Society.

[31]  A. Orpen,et al.  A ligand knowledge base for carbenes (LKB-C): maps of ligand space. , 2009, Dalton transactions.

[32]  S. Nolan,et al.  N-heterocyclic carbenes in late transition metal catalysis. , 2009, Chemical reviews.

[33]  E. Herdtweck,et al.  Complexation of (5H)-Dibenzo[a,d]cyclohepten-5-ylidene to Palladium(II) via the Diazo Route and Evidence of C−H···Pd Interactions , 2009 .

[34]  A. Spek,et al.  A molecular cage of nickel(II) and copper(I): a [{Ni(L)2}2(CuI)6] cluster resembling the active site of nickel-containing enzymes. , 2009, Chemical communications.

[35]  T. Tu,et al.  A Lutidine-Bridged Bis-Perimidinium Salt: Synthesis and Application as a Precursor in Palladium-Catalyzed Cross-Coupling Reactions , 2009 .

[36]  L. Cavallo,et al.  Understanding the M(NHC) (NHC = N-heterocyclic carbene) bond , 2009 .

[37]  F. Hahn,et al.  Heterocyclic carbenes: synthesis and coordination chemistry. , 2008, Angewandte Chemie.

[38]  C. Bielawski,et al.  N-Heterocyclic Carbene−Transition Metal Complexes: Spectroscopic and Crystallographic Analyses of π-Back-bonding Interactions , 2007 .

[39]  A. I. Korobkov,et al.  Design of Sterically Demanding, Electron-Rich Carbene Ligands with the Perimidine Scaffold , 2007 .

[40]  O. Kühl.  The chemistry of functionalised N-heterocyclic carbenes. , 2007, Chemical Society reviews.

[41]  E. Herdtweck,et al.  N-Heterocyclic Carbenes: Synthesis, Structures, and Electronic Ligand Properties , 2006 .

[42]  L. Cavallo,et al.  Steric and electronic effects in the bonding of N-heterocyclic ligands to transition metals , 2005 .

[43]  M. Lappert.  Contributions to the chemistry of carbenemetal chemistry , 2005 .

[44]  D. C. Graham,et al.  Dimerization mechanisms of heterocyclic carbenes , 2005 .

[45]  J. Harvey,et al.  When and how do diaminocarbenes dimerize? , 2004, Angewandte Chemie.

[46]  I. Özdemir,et al.  In situ generated palladium catalysts bearing 1,3-dialkylperimidin-2-yline ligands for Suzuki reactions of aryl chlorides , 2004 .

[47]  F. Hahn,et al.  Simple access to unsymmetrically substituted, saturated N-heterocyclic carbenes. , 2003, Angewandte Chemie.

[48]  G. Yap,et al.  Constructing a stable carbene with a novel topology and electronic framework. , 2003, Journal of the American Chemical Society.

[49]  Fröhlich,et al.  Evidence for an Equilibrium between an N-heterocyclic Carbene and Its Dimer in Solution. , 2000, Angewandte Chemie.

[50]  P. Lindner,et al.  THERMODYNAMICS OF A DIAMINOCARBENE-TETRAAMINOETHYLENE EQUILIBRIUM , 1999 .

[51]  M. Lappert.  The coordination chemistry of electron-rich alkenes (enetetramines) , 1988 .

[52]  C. A. Tolman,et al.  Steric effects of phosphorus ligands in organometallic chemistry and homogeneous catalysis , 1977 .

[53]  S. Trofimenko.  Boron-pyrazole chemistry. IV. Carbon- and boron-substituted poly[(1-pyrazolyl) borates] , 1967 .

[54]  D. Bourissou,et al.  Stable Carbenes. , 2000, Chemical reviews.

[55]  P. Hitchcock,et al.  Synthesis and characterisation of unusual tetraaminoalkenes (enetetramines) , 1992 .