The first enantioselective NHC-catalyzed activation of α-aryl substituted α,β-disubstituted unsaturated aldehyde is successfully developed via a highly-active acyl azolium intermediate. The new C1-symmetric biaryl-saturated imidazolium exhibits a superior ability to enable previously unavailable transformation, and the corresponding fully functionalized dihydropyranones are efficiently synthesi...

The first enantioselective synthesis of the fungal metabolite (+)-O-methylasparvenone was achieved in eight steps and 22% overall yield from inexpensive 3,4,5-trimethoxybenzaldehyde dimethyl acetal. Key steps include (i) early-stage asymmetric alkynylation of an aromatic aldehyde with a propiolate, (ii) intramolecular Friedel-Crafts acylation, and (iii) site-selective cleavage of an aryl methyl...

A simple and environmentally benign procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation of 2-naphthol with aromatic aldehyde in the presence of [Et3NH][HSO4] as an acidic ionic liquid catalyst under solvent-free conditions has been developed. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused s...

Aryl aldehyde activation: Oxidative activation of 2-methylindole-3-carboxaldehyde (I) through N-heterocyclic carbene (NHC) organocatalysis generates heterocyclic ortho-quinodimethane (II) as a key intermediate. This intermediate then undergoes formal [4+2] cycloaddition with trifluoromethyl ketones or isatins to form polycyclic lactones containing a quaternary carbon center.

A simple protocol for the efficient preparation of aryl and heteroaryl substituted dihydropyrimidinone has been achieved via initial Knoevenagel, subsequent addition, and final cyclization of aldehyde, ethylcyanoacetate, and guanidine nitrate in the presence of piperidine as a catalyst in solvent-free under microwave irradiation. The synthesized compounds showed a good anti-inflammatory, antiba...

A simple and environmentally benign procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation of 2-naphthol with aromatic aldehyde in the presence of [Et3NH][HSO4] as an acidic ionic liquid catalyst under solvent-free conditions has been developed. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused s...

The research in the field of asymmetric carbene organic catalysis has primarily focused on the activation of carbon atoms in non-aromatic scaffolds. Here we report a reaction mode of carbene catalysis that allows for aromatic aldehyde activation and remote oxygen atom functionalization. The addition of a carbene catalyst to the aldehyde moiety of 2-hydroxyl aryl aldehyde eventually enables dear...

The aldehyde tag is appropriate to selectively label proteins, prepare antibody-drug conjugates or immobilize enzymes antibodies for biotechnological and medical applications. cysteine within the consensus sequence CxPxR of specifically oxidized by formylglycine-generating enzyme (FGE) non-canonical electrophilic amino acid Cα-formylglycine (FGly). Subsequent reductive amination a common method...

A number of catalytic synthetic reactions have been reported which play the important role in stereochemistry compounds. The key to success this protocol was generation stereogenic centers 1, 4-Dihydropyrimidinones (DHPMs) and influence catalysts on their configuration. Waste brick dust found be an effective catalyst, generating chiral DHPMs derivatives using aryl aldehyde, urea, ethyl acetoace...

Synthesis of 2-[2-(2,6-dichlorophenyl)amino]phenylmethyl-3-[4-(2-substitutedphenyl-4-oxo-thiazolidinyl)aryl]-6-bromo quinazolin-4(3H)ones VIa-j have been achieved from the starting material 2-[(2,6-dichlorophenyl)amino] phenylacetic acid I to benzoxazine III, Further reaction with p-phenylindiamine and substituted aromatic aldehyde gave 2-[2-(2,6-dichlorophenyl)amino]phenyl methyl-3-(4-aminoary...