Hypervalent Iodine in the Synthesis of Bridgehead Heterocycles: A Facile Route to the Synthesis of 6‐Arylimidazo[2,1‐b]thiazoles Using [Hydroxy(tosyloxy)iodo]benzene

α‐Tosyloxyketones (2), readily accessible through hypervalent iodine oxidation of enolizable ketones (1) using [hydroxy(tosyloxy)iodo]benzene (HTIB) in acetonitrile, exclusively generates the 6‐arylimidazo[2,1‐b]thiazoles (4) on treatment with commercially available 2‐aminothiazole (3).     

Expeditious Approach to Coumarins via Pechmann Reaction Catalyzed by Molecular Iodine or AgOTf

An efficient and facile route for the synthesis of coumarins via the Pechmann reaction catalyzed by molecular iodine or AgOTf was described.     

Solvent‐Free Iodination of Arenes using Iodine–Silver Nitrate Combination

A simple and environmentally safe general method of iodination of aromatic substrates under sovent‐free conditions using the I₂/AgNO₃ combination in a solid state is reported. Both activated and deactivated aromatic compounds afford the respective aryl iodides in generally high yields (80–90%).     

Synthetic Approach to 4a-Methyltetrahydrofluorene-Type Diterpenoids via an Aromatic Oxidation of Phenol Derivatives

An intramolecular aromatic oxidation of a phenolic compound with a hypervalent iodine reagent afforded the coupling product, in which the coupling took place at the para-position of the methoxy goup of the starting material instead of the desired para-position of the isopropenyl group, unfortunately.      

Regioselective Synthesis of α‐Iodoacetates from Alkenes/Ammonium Acetate/I2 by Woodward's Reaction

Abstract

Regioselective synthesis of α‐iodoacetates from alkenes, ammonium acetate, and iodine in acetic acid is reported. The reaction is facile, fast, environmentally, friendly, and cost effective. α‐Iodoacetates are obtained from both acyclic and cyclic alkenes in high yields ranging from 80–95% within 10–20 min.     

Regioselective synthesis of pyrano[3,2-f]quinoline and phenanthroline derivatives using molecular iodine

A series of polysubstituted pyrano[3,2-f]quinoline and phenanthroline derivatives have been synthesized by molecular iodine-catalyzed tandem reaction of various propargylic alcohols with or without substituted amines in excellent yields. Moreover, the cyclized side products are also pyrano[3,2-f]quinoline and phenanthroline derivatives.     

Piperidine–iodine a dual system catalyst for synthesis of coumarin bearing pyrrolo[1,2-a]quinoxaline derivatives via a one-pot three-component reaction

The synthesis of 3-(4-alkyl-4,5-dihydropyrrolo[1,2-a]quinoxalin-4-yl)-2H-chromen-2-one derivatives by a three-component reaction of salicylaldehyde, β-keto esters, and 1-(2-aminophenyl)pyrrole using piperidine–iodine as a dual system catalyst is reported. Good yields, mild reaction conditions, and ease of handling are the main aspects of the method. The structural assignments are supported by ¹H NMR, ¹³C NMR, and X-ray crystallography data.     

One-Pot Synthesis and Applications of N-Heteroaryl Iodonium Salts

An efficient one-pot synthesis of N-heteroaryl iodonium triflates from the corresponding N-heteroaryl iodide and arene has been developed. The reaction conditions resemble our previous one-pot syntheses, with suitable modifications to allow N-heteroaryl groups. The reaction time is only 30 min, and no anion exchange is required. The obtained iodonium salts were isolated in a protonated form, these salts can either be employed directly in applications or be deprotonated prior to use. The aryl groups were chosen to induce chemoselective transfer of the heteroaryl moiety to various nucleophiles. The reactivity and chemoselectivity of these iodonium salts were demonstrated by selectively introducing a pyridyl moiety onto both oxygen and carbon nucleophiles in good yields.     

Transformations of iodine species inside elliptical channels of AlPO4‐11 crystals at low temperature: a Raman study

Raman spectra of iodine species confined in one‐dimensional elliptical channels of AlPO₄‐11 (AEL) crystals have been studied from room temperature down to −196 °C. As temperature decreases, thermal fluctuations of individual iodine molecules confined in AEL channels are slowed down and they prefer to rotate to channel axis direction, which increases the population of iodine molecules along channel axis (i.e., lying molecules and chains). Such temperature‐driven orientation transformation of iodine molecules is found to be reversible upon heating up to room temperature. The experimental observations are in good agreement with our theoretical simulations by molecular dynamics on low density iodine‐filled AEL crystals. We thus provide a new way to modulate the orientation of iodine molecules in nanochannels, which may have implications in low‐temperature‐sensitive nanoscale devices. Copyright © 2015 John Wiley & Sons, Ltd.