silica ferric hydrogensulfate is an efficient heterogeneous catalyst for the cyclization of 2- aminochalcones to the corresponding 2,3-dihydroquinolin- 4(1h)-ones. this intramolecular aza michael reaction was carried out in high yields using chalcones bearing of electron donating and electron withdrawing groups. the catalyst is reusable without significant decreases in its activity after four t...

An intramolecular enantioselective metal-catalyzed dearomatization reaction is described. This procedure allows the dearomatization of naphthalene derivatives through an electrophilic aromatic substitution-type reaction on a Pd(II) intermediate. The high yields and enantioselectivities achieved make this procedure a valuable method for synthetic chemists.

A highly regioselective domino metathesis reaction of 7-oxanorbornene was developed that employed an intramolecular association of an amide carbonyl group to a ruthenium metal centre. By using this reaction, twelve glutamate analogues inspired by dysiherbaine were efficiently synthesized over 12-14 steps; one of the analogues exhibited bioactivity consistent with central nervous system depression.

A new ring expansion of 2-aminobenzothiazoles with alkynyl carboxylic acids was developed, which allows for one-pot synthesis of 1,4-benzothiazines in moderate to excellent yields. The cascade reaction was achieved through decarboxylative coupling, nucleophilic ring-opening reaction and intramolecular hydroamination process.

Me(3)SiI-promoted reaction of salicylic aldehydes with β-dicarbonyl compounds provided a facile way to construct 4H-benzopyrans in moderate to good yields. This tandem reaction proceeds with high efficiency through nucleophilic addition, silyl enol ether formation, substitution, reduction, and intramolecular nucleophilic cyclization.

An efficient cascade reaction of 2,3-allenoic acids with dialkyl azodicarboxylate in the presence of PPh3 affording 1,2-bis(alkoxycarbonyl)pyrazol-3-ones in moderate yields has been developed. The reaction may proceed via the intramolecular Michael addition of the expected 2,3-allenoyl hydrazines.

A stereocontrolled total synthesis of (+)-lysergic acid (1) is achieved using three metal-catalyzed methodologies for the construction of three key rings. Highlights of the synthesis include Pd-catalyzed indole synthesis to form the B ring, a RCM reaction to form the D ring, and an intramolecular Heck reaction to form the C ring.

[reaction: see text] The total synthesis of (+)-sparteine was accomplished from 2,5-norbornadione in 15 steps and 15.7% overall yield. The key steps were two ring-expansion reactions, one involving an intramolecular Schmidt reaction and one using a novel variant of the photo-Beckmann rearrangement.

Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular Aza-Wittig cyclization in CH2Cl2 in excellent yields. The structures of the products were deduced from...

Azetidine is a prevalent structural motif found in various biologically active compounds. In this research paper, we report La(OTf) 3 -catalyzed intramolecular regioselective aminolysis of cis -3,4-epoxy amines to afford azetidines. This reaction proceeded high yields even the presence acid-sensitive and Lewis basic functional groups.