Highly efficient aza-Michael reactions of aromatic amines and N-heterocycles catalyzed by a basic ionic liquid under solvent-free conditions

A task-specific basic ionic liquid, [Bmim]OH, has been introduced as a catalyst for the aza-Michael addition of aromatic amines and N-heterocycles to cyclic or acyclic ketones under neat conditions. The catalyst can be recycled for subsequent reactions without any appreciable loss of efficiency.

[1]  J. Spencer,et al.  Convenient synthesis of Cbz-protected β-amino ketones by a copper-catalysed conjugate addition reaction , 2002 .

[2]  Shaolin Zhou,et al.  A green, ionic liquid and quaternary ammonium salt-catalyzed aza-Michael reaction of α,β-ethylenic compounds with amines in water , 2004 .

[3]  K. R. Seddon,et al.  The Heck reaction in ionic liquids: A multiphasic catalyst system , 1999 .

[4]  B. Ranu,et al.  Ionic liquid as catalyst and reaction medium. The dramatic influence of a task-specific ionic liquid, [bmIm]OH, in Michael addition of active methylene compounds to conjugated ketones, carboxylic esters, and nitriles. , 2005, Organic letters.

[5]  U. Kragl,et al.  Enzyme catalysis in ionic liquids: lipase catalysed kinetic resolution of 1-phenylethanol with improved enantioselectivity , 2001 .

[6]  E. Corey,et al.  Enantioselective Michael Addition of Nitromethane to α,β-Enones Catalyzed by Chiral Quaternary Ammonium Salts. A Simple Synthesis of (R)-Baclofen , 2000 .

[7]  H. Ishitani,et al.  Catalytic enantioselective addition to imines. , 1999, Chemical reviews.

[8]  C. Xia,et al.  Efficient synthesis of chlorohydrins : Ionic liquid promoted ring-opening reaction of epoxides and TMSCl , 2004 .

[9]  D. Bartak,et al.  Electrochemistry of carbonium ions in acidic media. 1. Triphenylmethyl ion in aluminum chloride containing melts , 1982 .

[10]  D. Kaufmann,et al.  Molten Salts as an Efficient Medium for Palladium Catalyzed C-C Coupling Reactions , 1996 .

[11]  Tom Welton,et al.  Diels-Alder reactions in room-temperature ionic liquids , 1999 .

[12]  Kun Qiao,et al.  Novel acidic ionic liquids catalytic systems for Friedel-Crafts alkylation of aromatic compounds with alkenes , 2004 .

[13]  K. Tomioka,et al.  Asymmetric synthesis of intermediates for otamixaban and premafloxacin by the chiral ligand-controlled asymmetric conjugate addition of a lithium amide. , 2006, The Journal of organic chemistry.

[14]  Sahid Hussain,et al.  Boric acid: a novel and safe catalyst for aza-Michael reactions in water , 2005 .

[15]  B. Banik,et al.  Bismuth nitrate-catalyzed versatile Michael reactions. , 2003, The Journal of organic chemistry.

[16]  P. Wasserscheid,et al.  Ionic Liquids-New "Solutions" for Transition Metal Catalysis. , 2000, Angewandte Chemie.

[17]  K. R. Rao,et al.  β-Cyclodextrin promoted aza-Michael addition of amines to conjugated alkenes in water , 2006 .

[18]  C. Qian,et al.  Basic ionic liquid as catalysis and reaction medium: a novel and green protocol for the Markovnikov addition of N-heterocycles to vinyl esters, using a task-specific ionic liquid, [bmIm]OH. , 2006, The Journal of organic chemistry.

[19]  Lei Yang,et al.  Highly efficient KF/Al2O3-catalyzed versatile hetero-Michael addition of nitrogen, oxygen, and sulfur nucleophiles to α,β-ethylenic compounds , 2005 .

[20]  P. Suarez,et al.  Ionic liquid (molten salt) phase organometallic catalysis. , 2002, Chemical reviews.

[21]  E. Marcantoni,et al.  Conjugate Addition of Amines to α,β-Enones Promoted by CeCl3·7H2O−NaI System Supported in Silica Gel , 2001 .

[22]  C. Gordon New developments in catalysis using ionic liquids , 2001 .

[23]  R. Varma,et al.  Microwave-assisted preparation of dialkylimidazolium tetrachloroaluminates and their use as catalysts in the solvent-free tetrahydropyranylation of alcohols and phenols. , 2002, Chemical communications.

[24]  S. Matsubara,et al.  Lanthanoid Triflate Catalyzed Conjugate Addition of Amines to α, β-Unsaturated Esters. A Facile Route to Optically Active β-Lactam , 1994 .

[25]  Kenneth R. Seddon,et al.  Ionic liquids. Green solvents for the future , 2000 .

[26]  M. Salunkhe,et al.  Lewis acidic ionic liquids for the synthesis of electrophilic alkenes via the Knoevenagel condensation , 2002 .

[27]  J. Dupont,et al.  Asymmetric hydrogenation of 2-arylacrylic acids catalyzed by immobilized Ru-BINAP complex in 1-n-butyl-3-methylimidazolium tetrafluoroborate molten salt , 1997 .

[28]  Sahid Hussain,et al.  Cu(acac)2 Immobilized in Ionic Liquids: A Recoverable and Reusable Catalytic System for Aza‐Michael Reactions , 2005 .

[29]  B. Eftekhari‐Sis,et al.  ZrOCl2·8H2O on montmorillonite K10 accelerated conjugate addition of amines to α,β-unsaturated alkenes under solvent-free conditions , 2006 .

[30]  Michael Arend,et al.  Modern Variants of the Mannich Reaction. , 1998, Angewandte Chemie.

[31]  P. Suarez,et al.  The use of new ionic liquids in two-phase catalytic hydrogenation reaction by rhodium complexes , 1996 .

[32]  J. Wilkes,et al.  Friedel-Crafts reactions in ambient-temperature molten salts , 1986 .

[33]  N. Azizi,et al.  LiClO4 Accelerated Michael addition of amines to α,β-unsaturated olefins under solvent-free conditions , 2004 .

[34]  J. E. Lier,et al.  Silica gel supported TaBr5: new catalyst for the facile and rapid cyclization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under solvent-free conditions , 2006 .

[35]  J. Dupont,et al.  Regioselective synthesis of 2-arylpropionic esters by palladium-catalyzed hydroesterification of styrene derivatives in molten salt media , 1998 .

[36]  A. Bedekar,et al.  Clay catalyzed chemoselective Michael type addition of aliphatic amines to α,β-ethylenic compounds , 2001 .

[37]  W. Herrmann,et al.  Nonaqueous ionic liquids: superior reaction media for the catalytic Heck-vinylation of chloroarenes , 2000, Chemistry.

[38]  H. García,et al.  Assessment of the suitability of imidazolium ionic liquids as reaction medium for base-catalysed reactions: Case of Knoevenagel and Claisen–Schmidt reactions , 2004 .

[39]  H. Ishitani,et al.  Enantioselective Mannich-Type Reactions Using a Novel Chiral Zirconium Catalyst for the Synthesis of Optically Active β-Amino Acid Derivatives , 2000 .

[40]  C. Tomasini,et al.  Asymmetric synthesis of ß-amino acids and α-substituted β-amino acids , 1996 .

[41]  R. Cooks,et al.  Proton affinities of N-heterocyclic carbene super bases. , 2005, Organic letters.

[42]  Shaolin Zhou,et al.  The first ionic liquids promoted conjugate addition of azide ion to α,β-unsaturated carbonyl compounds , 2004 .

[43]  J. Brunet,et al.  Ionic liquids as solvents for the regioselective O-alkylation of C/O ambident nucleophiles. , 1992 .

[44]  K. R. Seddon,et al.  Regioselective alkylation in ionic liquids , 1998 .

[45]  J. Yadav,et al.  Aza-Michael Reactions in Ionic Liquids. A Facile Synthesis of β-Amino Compounds , 2003 .

[46]  P. Das,et al.  Synthesis of β-amino esters via aza-michael addition of amines to alkenes promoted on silica: A useful and recyclable surface , 2004 .

[47]  C. Song,et al.  Practical method to recycle a chiral (salen)Mn epoxidation catalyst by using an ionic liquid , 2000 .

[48]  K. R. Seddon,et al.  Diels–Alder reactions in ionic liquids. A safe recyclable alternative to lithium perchlorate–diethyl ether mixtures , 1999 .

[49]  T. Loh,et al.  Indium Trichloride-Catalyzed Conjugate Addition of Amines to α,β-Ethylenic Compounds in Water , 1998 .

[50]  P. Wasserscheid,et al.  LINEAR DIMERISATION OF BUT-1-ENE IN BIPHASIC MODE USING BUFFERED CHLOROALUMINATE IONIC LIQUID SOLVENTS , 1999 .

[51]  E. Juaristi Enantioselective synthesis of β-amino acids , 1997 .

[52]  G. Jenner Catalytic high pressure synthesis of hindered β-aminoesters , 1995 .

[53]  T. Konakahara,et al.  InBr3-catalyzed intramolecular cyclization of 2-alkynylanilines leading to polysubstituted indole and its application to one-pot synthesis of an amino acid precursor , 2006 .