Mono-, bis- and tris-piperidine fused imidazolinium salts: their in situ catalytic applications for CC bond formation in aqueous solutions

The 1,5,6,7,8,8a-hexahydroimidazo[1,5-a]pyridine, 3, was quaternized with 2-(bromomethyl-1,3,5-trimethylbenzene, 1,4-bis(bromomethyl)-2,3,5,6-tetramethylbenzene, 2,4-bis(bromomethyl)-1,3,5-trimethylbenzene, 1,3,5-tris(bromomethyl)-2,4,6-trimethylbenzene and 1,3,5-tris(bromomethyl)-2,4,6-triethylbenzene to obtain mono-, bis- and tris-imidazolinium salts (4–7) which were characterized by elemental analysis and NMR spectroscopy. In order to understand the effects of these changes on the N-substituent and how they translate to catalytic activity, these new salts (4–7) with Pd(OAc)2 were applied as in situ catalysts for Suzuki-Miyaura and Heck-Mirozoki cross-coupling reactions of aryl chlorides and aryl bromides, respectively. The tris-imidazolinium salts (7) were found to be more efficient than the related analogs 4–6. Copyright © 2009 John Wiley & Sons, Ltd.

[1]  K. Cavell,et al.  Synthesis of pyrazine-bridged diimidazolium salts and their application in palladium catalyzed Heck-type coupling reactions , 2009 .

[2]  F. Glorius,et al.  Surveying sterically demanding N-heterocyclic carbene ligands with restricted flexibility for palladium-catalyzed cross-coupling reactions. , 2008, Accounts of chemical research.

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

[4]  F. Hahn,et al.  Annulated N-Heterocyclic Carbene Ligands Derived from 2-Methylaminopiperidine: Their Complexes and Catalytic Applications , 2008 .

[5]  I. Özdemir,et al.  Synthesis and use of mono- or bisxylyl linked bis(benzimidazolium) bromides as carbene precursors for C–C bond formation reactions , 2008 .

[6]  H. Butenschön,et al.  Suzuki–Miyaura coupling in the presence of (2,2,2-triferrocenylethyl)diphenylphosphane , 2008 .

[7]  M. Organ,et al.  Palladium complexes of N-heterocyclic carbenes as catalysts for cross-coupling reactions--a synthetic chemist's perspective. , 2007, Angewandte Chemie.

[8]  E. Álvarez,et al.  Imidazo[1,5-a]pyridin-3-ylidene/Thioether Mixed C/S Ligands and Complexes Thereof§ , 2007 .

[9]  I. Özdemir,et al.  Palladium-Catalyzed Heck Reaction of Aryl Bromides in Aqueous Media Using Tris(N-Heterocyclic Carbene) Ligands , 2007 .

[10]  J. Mata,et al.  Structural and catalytic properties of chelating bis- and tris-N-heterocyclic carbenes , 2007 .

[11]  S. Bellemin‐Laponnaz,et al.  Mixed oxazoline-carbenes as stereodirecting ligands for asymmetric catalysis , 2007 .

[12]  E. Herdtweck,et al.  Chiral N-Heterocyclic Carbenes with Restricted Flexibility in Asymmetric Catalysis† , 2007 .

[13]  K. Cavell,et al.  Chiral N-heterocyclic carbene ligands based on a biisoquinoline template. , 2006, Dalton transactions.

[14]  B. Çetinkaya,et al.  1,3-Diarylimidazolidin-2-ylidene (NHC) complexes of Pd(II): Electronic effects on cross-coupling reactions and thermal decompositions , 2006 .

[15]  E. Herdtweck,et al.  Chiral N-Heterocyclic Carbene Ligands Derived from 2,2‘-Bipiperidine and Partially Reduced Biisoquinoline: Rhodium and Iridium Complexes in Asymmetric Catalysis† , 2006 .

[16]  I. Özdemir,et al.  Use of bis(benzimidazolium)–palladium system as a convenient catalyst for Heck and Suzuki coupling reactions of aryl bromides and chlorides , 2006 .

[17]  Qiang Feng,et al.  Novel hexadentate imidazolium salts in the rhodium-catalyzed addition of arylboronic acids to aldehydes , 2006 .

[18]  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 .

[19]  F. Glorius,et al.  Imidazo[1,5-a]pyridine-3-ylidenes - pyridine derived N-heterocyclic carbene ligands , 2005 .

[20]  M. Alcarazo,et al.  Imidazo[1,5-a]pyridine: a versatile architecture for stable N-heterocyclic carbenes. , 2005, Journal of the American Chemical Society.

[21]  S. Bellemin‐Laponnaz,et al.  Chiral N-heterocyclic carbenes as stereodirecting ligands in asymmetric catalysis. , 2004, Chemical Society reviews.

[22]  R. Crabtree,et al.  Recent homogeneous catalytic applications of chelate and pincer N-heterocyclic carbenes , 2004 .

[23]  S. Caddick,et al.  Suzuki–Miyaura cross-coupling of aryl and alkyl halides using palladium/imidazolium salt protocols , 2004 .

[24]  K. Cavell,et al.  Redox processes involving hydrocarbylmetal (N-heterocyclic carbene) complexes and associated imidazolium salts: ramifications for catalysis , 2004 .

[25]  Jingping Liu,et al.  Suzuki cross-coupling mediated by tetradentate N-heterocyclic carbene (NHC)-palladium complexes in an environmentally benign solvent. , 2003, Organic & biomolecular chemistry.

[26]  K. Burgess,et al.  Chiral N-heterocyclic carbene-transition metal complexes in asymmetric catalysis , 2003 .

[27]  Yongjun Tang,et al.  A new entry to N-heterocyclic carbene chemistry: synthesis and characterisation of a triscarbene complex of thallium(I). , 2003, Chemical communications.

[28]  W. Herrmann.  N-heterocyclic carbenes: a new concept in organometallic catalysis. , 2002, Angewandte Chemie.

[29]  E. Anslyn,et al.  Metal triggered fluorescence sensing of citrate using a synthetic receptor , 2001 .

[30]  M. Trudell,et al.  Palladium-bisimidazol-2-ylidene complexes as catalysts for general and efficient Suzuki cross-coupling reactions of aryl chlorides with arylboronic acids , 2000 .

[31]  R. Grubbs,et al.  Synthesis and activity of a new generation of ruthenium-based olefin metathesis catalysts coordinated with 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ligands. , 1999, Organic letters.

[32]  F. Hampel,et al.  Generation and Trapping Reactions of a Formal 1:1 Complex between Singlet Carbon and 2,2'-Bipyridine. , 1998, Angewandte Chemie.

[33]  Chao-Jun Li,et al.  Organic reactions in aqueous media , 1997 .

[34]  W. Herrmann,et al.  Metal Complexes of N‐Heterocyclic Carbenes—A New Structural Principle for Catalysts in Homogeneous Catalysis , 1995 .

[35]  W. Herrmann,et al.  Flüchtige Metallalkoxide nach dem Konzept der Donorfunktionalisierung , 1995 .

[36]  A. V. D. Made,et al.  A convenient procedure for bromomethylation of aromatic compounds. Selective mono-, bis-, or trisbromomethylation , 1993 .

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

[38]  M. Lappert,et al.  An electron-rich olefin as a source of co-ordinated carbene; synthesis of trans-PtCl2[C(NPhCH2)2]PEt3 , 1971 .

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

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