A one-pot, two step synthesis of highly substituted imidazoles has been carried out in good to excellent yields for the first time via a cascade intermolecular aza-SN2'-intramolecular aza-Michael addition involving a variety of Morita-Baylis-Hillman acetates of nitroalkenes and amidines in the presence of DABCO at room temperature. The synthetic and biological utility of the products has been d...

C(alpha)-Tetrasubstituted alpha-amino acids are important building blocks for the synthesis of peptidemimetics with stabilized secondary structure, because of their ability to rigidify the peptide backbone. Recently our group reported a new class of cyclic C(alpha)-tetrasubstituted tetrahydrofuran alpha-amino acids prepared from methionine and aromatic aldehydes. We now report the extension of ...

A quantitative structure activity relationship (QSAR) study on tetrasubstituted pyrazoles as high affinity ligands for the estrogen receptor (both ERα and ERβ subtypes) have been performed using various combinations of hydrophobic (MlogP), steric (MR) and electronic (Xeq) descriptors. The regression analysis of the data has shown better results in multiparametric regressions upon introduction o...

Oxime-directed catalytic asymmetric hydroboration is diverted to catalytic asymmetric hydrogenation (CAH) upon the addition of a proton source, such as MeOH, or by running the reaction under a hydrogen atmosphere. A borane (e.g., pinacolborane) is required to promote CAH. Tri- and tetrasubstituted alkenes, including the challenging all-alkyl tetrasubstituted alkenes, undergo CAH with enantiomer...

N-aryl imidazoles play an important role as structural and functional units in many natural products and biologically active compounds. Herein, we report a photocatalytic route for the C-N cross-coupling reactions over a Cu/graphene catalyst, which can effectively catalyze N-arylation of imidazole and phenylboronic acid, and achieve a turnover frequency of 25.4 h(-1) at 25°C and the irradiation...

A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H)-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. ...

An enantioselective Friedel-Crafts alkylation with alpha,beta-unsaturated 2-acyl imidazoles and electron-rich aromatic nucleophiles catalyzed by bis(oxazolinyl)pyridine-scandium(III) triflate complexes has been accomplished. These alpha,beta-unsaturated 2-acyl imidazoles are effective electrophiles for the Friedel-Crafts reaction. The resulting adduct 2-acyl imidazole is easily converted to ami...

The first examples of highly enantioselective Narasaka-Heck cyclizations are described. A SPINOL-derived P,N-ligand system enables Pd-catalyzed 5-exo cyclization of a range of oxime esters with sterically diverse trisubstituted alkenes to generate dihydropyrroles containing tetrasubstituted nitrogen-bearing stereocenters in 56 to 86% yield and 90 : 10 to 95 : 5 e.r. These processes are rare exa...

The microwave assisted and solvent free synthesis of title compounds is described in this protocol. Ten new aryl imidazoles, which are incorporated with the chemotherapeutic pharmacophores, have been synthesized by adopting one pot multicomponent reaction. First, primary aromatic or heteryl amine has been condensed with aryl or heteryl aldehydes to afford corresponding Schiff base. The Schiff b...

two  simple  protocols  for  the  synthesis  of  1,  2,  4,  5-  tetrasubstitutedimidazoles  using  nano-spa  as  a  reusable,  eco-  friendly,  inexpensive,  and  efficient  catalyst  are  reported.  short   reaction  times,  high  yields,  scale-up  and  easy  workup  are  the   advantages of these protocols.