Dess-Martin Periodinane Mediated Intramolecular Cyclization of Phenolic Azomethines: A Solution-Phase Strategy toward Benzoxazoles and Benzothiazoles

Application of Vitreoscilla Hemoglobin as a Green and Efficient Biocatalyst for the Synthesis of Benzoxazoles in Water

We report an efficient and eco-friendly method for the Vitreoscilla hemoglobin (VHb)-catalyzed synthesis of benzoxazoles in water at room temperature. tert-Butyl hydroperoxide and 2,2,6,6-tetramethyl-1-piperidinyloxy were used as oxidant and radical scavenger, respectively. A total of 27 functionally diverse benzoxazoles were prepared in moderate to high yields (62 %-94 %) by the annulation reaction of phenols with amines in the presence of VHb in 1 h. Thus, this method is highly viable for practical applications. This work broadens the application of hemoglobin to organic synthesis.

Dess-Martin Periodinane-Mediated Oxidative Coupling Reaction of Isoquinoline with Benzyl Bromide

Dess-Martin periodinane (DMP) is a broadly applicable oxidant in chemical synthesis. In this work, an efficient and convenient synthesis of N-substituted isoquinolinone derivatives mediated by DMP was achieved through the oxidative coupling reaction of functionalized isoquinoline with readily available benzyl bromide, which is a metal-free, mild, and practical method for synthesizing isoquinoline-1,3-dione or isoquinoline-1,3,4-trione derivatives in excellent yields. The H₂O¹⁸-labeling experiment was performed to gain insight into the possible mechanism for this reaction.

Synthesis of benzoxazoles via the copper-catalyzed hydroamination of alkynones with 2-aminophenols

We describe herein the synthetic method to benzoxazole derivatives via the copper-catalyzed hydroamination of alkynones with 2-aminophenols.

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

Hypervalent iodine reagents have been developed as highly valuable reagents in synthetic organic chemistry during the past few decades. These reagents have been identified as key replacements of various toxic heavy metals in organic synthesis. Various synthetically and biologically important scaffolds have been developed using hypervalent iodine reagents either in stoichiometric or catalytic amounts. In addition, hypervalent iodine reagents have been employed for the synthesis of spirocyclic scaffolds via dearomatization processes. In this review, various approaches for the synthesis of spirocyclic scaffolds using hypervalent iodine reagents are covered including their stereoselective synthesis. Additionally, the applications of these reagents in natural product synthesis are also covered.

Transition-metal-free synthesis of oxazoles: valuable structural fragments in drug discovery

This review article encapsulates the recent developments in the metal-free approaches used to construct oxazole moiety.

Efficient construction of C–S and C–N bonds via metal-free reductive coupling of N-tosylhydrazones with benzo[d]thiazole-2-thiol

An efficient procedure for the synthesis of diverse benzo[d]thiazole derivatives has been developed via metal-free reductive coupling of N-tosylhydrazones with benzo[d]thiazole-2-thiols.

KI-catalyzed arylation of benzothiazoles from the coupling of aryl aldehydes with benzothiazoles in neat water

A KI-catalyzed oxidative coupling of benzothiazoles with aryl aldehydes using TBHP as an oxidant in neat water under metal free conditions is described.

Copper-catalyzed synthesis of substituted benzothiazoles via condensation of 2-aminobenzenethiols with nitriles

An efficient and convenient method was developed for the formation of 2-substituted benzothiazoles via a copper-catalyzed condensation of 2-aminobenzenethiols with nitriles. The developed method is applicable to a wide range of nitriles containing different functional groups furnishing excellent yields of the corresponding products.

Hybrids of privileged structures benzothiazoles and pyrrolo[2,1-c] [1,4]benzodiazepin-5-one, and diversity-oriented synthesis of benzothiazoles

Privileged structures like Benzothiazole and Pyrrolobenzodiazepine offer wonderful opportunity to explore in anti-cancer drug discovery as a mean to counter drug-resistance problem. BT-PBD hybrids and diverse BT derivatives have been synthesized and their in vitro cytotoxic activities were screened against five cancer cell lines have been discussed. The novel compounds showed promising results as compared with the marketed drug etoposide and could well be used in future anti-cancer drug development studies.