Synthesis of backbone P-functionalized imidazol-2-ylidene complexes: en route to novel functional ionic liquids.

1-Alkyl-3-methyl-4-diphenylphosphoryl-imidazolium hydrogensulfate (4a,b) (a: R(1) = R(2) = Me; b: R(1) = (i)Pr, R(2) = Me) and 1-alkyl-3-methyl-4,5-bis(diphenylphosphoryl)imidazolium hydrogensulfate (6a,c) (c: R(1) = (n)Bu, R(2) = Me) were obtained selectively and in good yields by oxidative desulfurization of 1-alkyl-3-methyl-4-diphenylphosphino-imidazole-2-thiones (2a,b) and 1-n-butyl-3-methyl-4,5-bis(diphenylphosphoryl)imidazole-2-thione (3c) or 1,3-dimethyl-4-diphenylthiophosphoryl-5-diphenylphosphino-imidazole-2-thione (5a), respectively, with hydrogen peroxide. Synthesis of phosphoryl functionalized imidazol-2-ylidene complexes of group VI metal pentacarbonyls (7a-9a) and (10b-12b) and bis(phosphoryl) functionalized imidazol-2-ylidene complexes of group VI metal pentacarbonyls (13c-15c) and (16a) with low steric demand (methyl, isopropyl, n-butyl) at both N-centers was achieved through deprotonation of imidazolium salts (4a,b) and (6a,c), respectively,-having HSO(4)(-) as a counterion-with potassium tert-butoxide followed by rapid addition of metal pentacarbonyl acetonitrile complexes [M(CO)(5)(CH(3)CN)] (M = Cr, Mo, W). The products were unambiguously characterized by elemental analyses, spectroscopic and spectrometric methods, and in addition, by single-crystal X-ray structure studies in the cases of 4b, 8a, 15c, and 16a; the latter two reveal imidazole ring bond distance alternation in contrast to 8a.

[1]  Joshua I. Bates,et al.  4-Phosphino-Substituted N-Heterocyclic Carbenes (NHCs) from the Abnormal Reaction of NHCs with Phosphaalkenes , 2012 .

[2]  J. Ruiz,et al.  A 4,5-diphosphino-substituted imidazolium salt: a building block for the modular synthesis of mixed diphosphine-NHC heterometallic complexes. , 2012, Chemistry.

[3]  G. Schnakenburg,et al.  Synthesis, structure and reactivity of 4-phosphanylated 1,3-dialkyl-imidazole-2-thiones. , 2012, Dalton transactions.

[4]  S. Sakaguchi,et al.  Iridium complex bearing a chiral hydroxy-amide functionalized N-heterocyclic carbene: a catalyst precursor for asymmetric transfer hydrogenation , 2011 .

[5]  Isidro M. Pastor,et al.  (NHC)Palladium Complexes from Hydroxy‐Functionalized Imidazolium Salts as Catalyst for the Microwave‐Accelerated Fluorine‐Free Hiyama Reaction , 2011 .

[6]  D. Curran,et al.  Ring lithiation and functionalization of imidazol-2-ylidene-boranes. , 2011, Organic letters.

[7]  G. Bertrand,et al.  A Brief Survey of our Contribution to Stable Carbene Chemistry. , 2011, Organometallics.

[8]  A. J. Arduengo.  N-Heterocyclic Carbenes , 2011 .

[9]  C. Topf,et al.  Synthesis and Characterization of Silver(I), Gold(I), and Gold(III) Complexes Bearing Amino-Functionalized N-Heterocyclic Carbenes , 2011 .

[10]  G. Bertrand,et al.  Facile preparation of homo- and hetero-dimetallic complexes with a 4-phosphino-substituted NHC ligand. Toward the design of multifunctional catalysts. , 2011, Chemistry, an Asian journal.

[11]  A. Kennedy,et al.  Reactivity of [Ru-3(CO)(12)] with a phosphine-functionalized Imidazol-2-ylidene and Its imidazolium salt , 2011 .

[12]  H. Schaefer,et al.  Anionic N-Heterocyclic Dicarbene−Borane Binuclear Complexes , 2011 .

[13]  A. A. Yurchenko,et al.  N-phosphorylated imidazolium salts as precursors to 2- and 5-phosphorylated imidazoles and new imidazol-2-ylidenes featuring the PNCN unit. , 2010, The Journal of organic chemistry.

[14]  H. Schaefer,et al.  A viable anionic N-heterocyclic dicarbene. , 2010, Journal of the American Chemical Society.

[15]  G. Bertrand,et al.  Isolation of a carbene-stabilized phosphorus mononitride and its radical cation (PN+*). , 2010, Angewandte Chemie.

[16]  D. Stalke,et al.  A facile route to functionalized N-heterocyclic carbenes (NHCs) with NHC base-stabilized dichlorosilylene. , 2010, Journal of the American Chemical Society.

[17]  G. Bertrand,et al.  Synthesis of 4- and 4,5-functionalized imidazol-2-ylidenes from a single 4,5-unsubstituted imidazol-2-ylidene. , 2010, Journal of the American Chemical Society.

[18]  M. Scheer,et al.  P4 activation by main group elements and compounds. , 2010, Chemical reviews.

[19]  P. Kennepohl,et al.  Abnormal reactivity of an N-heterocyclic carbene (NHC) with a phosphaalkene: a route to a 4-phosphino-substituted NHC. , 2009, Angewandte Chemie.

[20]  G. Frenking,et al.  N-heterocyclic carbene stabilized digermanium(0). , 2009, Angewandte Chemie.

[21]  V. Lynch,et al.  Redox-Active N-Heterocyclic Carbenes: Design, Synthesis, and Evaluation of Their Electronic Properties , 2009 .

[22]  Yuzhong Wang,et al.  Unique homonuclear multiple bonding in main group compounds. , 2009, Chemical communications.

[23]  Lingbing Kong,et al.  Dehydrochlorination to Silylenes by N-Heterocyclic Carbenes , 2009 .

[24]  G. Schnakenburg,et al.  SiBr2(Idipp): a stable N-heterocyclic carbene adduct of dibromosilylene. , 2009, Angewandte Chemie.

[25]  D. Stalke,et al.  Lewis base stabilized dichlorosilylene. , 2009, Angewandte Chemie.

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

[27]  C. Cannon,et al.  The medicinal applications of imidazolium carbene-metal complexes. , 2009, Chemical reviews.

[28]  Amitabha Bhattacharyya,et al.  Coinage metal-N-heterocyclic carbene complexes. , 2009, Chemical reviews.

[29]  P. Arnold,et al.  F-block N-heterocyclic carbene complexes. , 2007, Chemical reviews.

[30]  Manoja K. Samantaray,et al.  Rare [(NHC)2Ni-OH]-Type Terminal Nickel Hydroxo and [(NHC)2Ni]-Type Complexes of N/O-Functionalized N-Heterocyclic Carbenes as Precatalysts for Highly Desirable Base-Free Michael Reactions in Air at Ambient Temperature , 2009 .

[31]  J. Mata,et al.  Complexes with poly(N-heterocyclic carbene) ligands: structural features and catalytic applications. , 2009, Chemical reviews.

[32]  G. Yap,et al.  Synthesis and Structure of an Amino-Linked N-Heterocyclic Carbene and the Reactivity of its Aluminum Adduct , 2009 .

[33]  G. Bertrand,et al.  Soluble Allotropes of Main-Group Elements , 2008, Science.

[34]  J. Bode,et al.  A modular synthesis of chiral aminoindanol-derived imidazolium salts , 2008 .

[35]  K. Park,et al.  Synthesis of chromium N -heterocyclic carbene complexes using chromium Fischer carbenes as a source of chromium carbonyls , 2007 .

[36]  J. Hedrick,et al.  Organocatalytic ring-opening polymerization. , 2007, Chemical reviews.

[37]  D. Enders,et al.  Organocatalysis by N-heterocyclic carbenes. , 2007, Chemical reviews.

[38]  P. Schreiner,et al.  Oxidative Desulfurization of Azole‐2‐thiones with Benzoyl Peroxide: Syntheses of Ionic Liquids and Other Azolium Salts , 2007 .

[39]  M. Weck,et al.  Supported N-heterocyclic carbene complexes in catalysis , 2007 .

[40]  Isidro M. Pastor,et al.  Solvent-free direct regioselective ring opening of epoxides with imidazoles , 2007 .

[41]  K. Udachin,et al.  Reactivity of electrophilic micro-phosphinidene complexes with N-heterocyclic carbenes: formation of the first main group element adducts of 'abnormal' carbene ligands. , 2006, Chemical communications.

[42]  W. Herrmann,et al.  Tetrazole and triazole carbene complexes of group 6 metal carbonyls , 2006 .

[43]  Manuel Alcarazo,et al.  Convenient, scalable and flexible method for the preparation of imidazolium salts with previously inaccessible substitution patterns. , 2006, Chemical communications.

[44]  F. Rominger,et al.  First examples of dipyrido[1,2-c:2′,1′-e]imidazolin-7-ylidenes serving as NHC-ligands: Synthesis, properties and structural features of their chromium and tungsten pentacarbonyl complexes , 2005 .

[45]  W. Marshall,et al.  The generation of a metallocene-fused imidazol-2-ylidene and its mercury complex. , 2005, Angewandte Chemie.

[46]  W. Marshall,et al.  A bimetallic complex containing a cyclopentadienyl-annulated imidazol-2-ylidene. , 2005, Journal of the American Chemical Society.

[47]  F. Hahn,et al.  Template synthesis of tungsten complexes with saturated N-heterocyclic carbene ligands. , 2005, Chemical communications.

[48]  W. Marshall,et al.  A zwitterionic cyclopentadienyl annulated imidazolium salt , 2005 .

[49]  F. Hahn,et al.  Spirocyclic diaminocarbenes: synthesis, coordination chemistry, and investigation of their dimerization behavior. , 2005, Chemistry.

[50]  IIIAnthony J. Arduengo,et al.  Heteroferrocene: The Synthesis of Bis[(3a,4,5,6,6a-η)-1,3,4,5,6-pentamethylcyclopenta[d]imidazo-2-thionoyl]iron(II) , 2005 .

[51]  H. Sakurai,et al.  Synthesis and oxidation of (benzimidazolylidene)Cr(CO) 5 complexes , 2005 .

[52]  G. Enright,et al.  A stable N-heterocyclic carbene with a diboron backbone. , 2005, Journal of the American Chemical Society.

[53]  F. Hahn,et al.  Synthesis of benzannulated N-heterocyclic carbene ligands by a template synthesis from 2-nitrophenyl isocyanide. , 2004, Chemistry.

[54]  C. Crudden,et al.  Stability and reactivity of N-heterocyclic carbene complexes , 2004 .

[55]  Ching-Han Hu,et al.  A new tridentate pincer phosphine/n-heterocyclic carbene ligand: palladium complexes, their structures, and catalytic activities. , 2004, Inorganic chemistry.

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

[57]  G. Morel.  A novel and convenient approach to 2-unsubstituted imidazolium and thiazolium salts , 2003 .

[58]  F. Hahn,et al.  Template synthesis of benzannulated N-heterocyclic carbene ligands. , 2003, Chemistry.

[59]  Michelle Taylor,et al.  A highly stable N-heterocyclic carbene complex of trichloro-oxo-vanadium(V) displaying novel Cl-Ccarbene bonding interactions. , 2003, Journal of the American Chemical Society.

[60]  Hyunik Shin,et al.  Efficient Synthesis of 1-Substituted-5-Hydroxymethylimidazole Derivatives: Clean Oxidative Cleavage of 2-Mercapto Group1 , 2002 .

[61]  Daniel J. Williams,et al.  1-Methyl-3-alkyl-2(3H)imidazolethione Complexes of Metal Halides: A Thematic-Ligand Approach to Involve Undergraduates in Research Projects , 2002 .

[62]  M. Tafipolsky,et al.  Electron delocalization in acyclic and N-heterocyclic carbenes and their complexes: a combined experimental and theoretical charge-density study. , 2002, Journal of the American Chemical Society.

[63]  C. Bolm,et al.  The First Planar-Chiral Stable Carbene and Its Metal Complexes , 2002 .

[64]  W. Marshall,et al.  A Tris(trifluoromethyl)antimony Adduct of a Nucleophilic Carbene: Geometric Distortions in Carbene Adducts , 1999 .

[65]  Anthony J. Arduengo,et al.  Looking for Stable Carbenes: The Difficulty in Starting Anew , 1999 .

[66]  F. Hahn,et al.  N,N'-Bis(2,2-dimethylpropyl)benzimidazolin-2-ylidene: a stable nucleophilic carbene derived from benzimidazole. , 1999 .

[67]  Gene-Hsiang Lee,et al.  Metal Ion Mediated Transfer and Cleavage of Diaminocarbene Ligands , 1999 .

[68]  B. Bildstein,et al.  N-Heterocyclic carbenes with N-ferrocenyl-N′-methyl-substitution: synthesis, reactivity, structure and electrochemistry , 1999 .

[69]  William J. Marshall,et al.  1,3,4,5-TETRAPHENYLIMIDAZOL-2-YLIDENE THE REALIZATION OF WANZLICK'S DREAM , 1998 .

[70]  B. Bildstein,et al.  Imidazoline-2-ylidene metal complexes with pendant ferrocenyl substituents , 1998 .

[71]  M. Wenzel,et al.  A Novel Synthesis of Tetraaminoethenes by Reduction of Oxalic Amidines and Subsequent Electrophilic Substitution , 1998 .

[72]  H. V. Rasika Dias,et al.  An Air Stable Carbene and Mixed Carbene “Dimers” , 1997 .

[73]  W. Herrmann,et al.  Metal Complexes of Chiral Imidazolin-2-ylidene Ligands , 1997 .

[74]  W. Marshall,et al.  A Carbene−Phosphorus(V) Adduct , 1997 .

[75]  W. Herrmann,et al.  Heterocyclic Carbenes: A High‐Yielding Synthesis of Novel, Functionalized N‐Heterocyclic Carbenes in Liquid Ammonia , 1996 .

[76]  W. Herrmann,et al.  Chiral Heterocylic Carbenes in Asymmetric Homogeneous Catalysis , 1996 .

[77]  W. Herrmann,et al.  N-heterocyclic carbenes as ligands in high-valent molybdenum and tungsten complexes , 1996 .

[78]  W. Herrmann,et al.  Heterocyclische Carbene IV. Metallkomplexe mit heterocyclischen Carben-Liganden: Synthese, Struktur, Strukturdynamik , 1995 .

[79]  W. Herrmann,et al.  Nucleophilic cyclocarbenes as ligands in metal halides and metal oxides , 1994 .

[80]  R. Boese,et al.  Heterozyklen als liganden: XX. Spektroskopische und strukturelle charakterisierung von pentacarbonylmetall-komplexen der imidazol-2-ylidene☆ , 1994 .

[81]  A. J. Arduengo,et al.  LOW-COORDINATE CARBENE COMPLEXES OF NICKEL(0) AND PLATINUM(0) , 1994 .

[82]  W. Herrmann,et al.  Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen: CXXVI. Heterocyclen-Carbene als phosphananaloge Liganden in Metallkomplexen , 1993 .

[83]  N. Kuhn,et al.  Synthesis of Imidazol-2-ylidenes by Reduction of Imidazole-2(3H)-thiones , 1993 .

[84]  K. Al-farhan.  Crystal structure of triphenylphosphine oxide , 1992 .

[85]  A. J. Arduengo,et al.  Electronic stabilization of nucleophilic carbenes , 1992 .

[86]  Richard L. Harlow,et al.  A stable crystalline carbene , 1991 .

[87]  F. Leeper,et al.  Synthesis and structure of bridged thiazolium salts , 1988 .

[88]  L. Field,et al.  THIONO COMPOUNDS. 5. PREPARATION AND OXIDATION OF SOME THIONO DERIVATIVES OF IMIDAZOLES , 1985 .

[89]  U. Schubert,et al.  Kristall- und molekülstruktur von pentacarbonyltetrahydrofuran-chrom(0) , 1978 .

[90]  U. Koelle.  Aminoxidinduzierte ligandensubstitution an metallcarbonylen , 1977 .

[91]  K. Öfele.  1,3-Dimethyl-4-imidazolinyliden-(2)-pentacarbonylchrom ein neuer übergangsmetall-carben-komplex , 1968 .

[92]  H. Wanzlick,et al.  Direct Synthesis of a Mercury Salt‐Carbene Complex , 1968 .

[93]  Reuben G. Jones,et al.  Studies on Imidazoles. VI. Synthesis of 4,5-Imidazoledicarboxylates , 1952 .