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Next-generation technology starts with iodine
Published in Tatsuo Kaiho, Iodine Made Simple, 2017
Iodine can easily expand in valence to form a trivalent or pentavalent hypervalent iodine compound, exceeding the Octet rule. For example, a trivalent iodine compound has the following structure. The central iodine atom creates a plane with two unshared electron pairs and one σ bond, and a ligand with high electronegativity (L) forms a bond at the apical position orthogonally intersecting that plane. The hypervalent bond in this apical position has a longer bond distance than the σ bond, and has high reactivity because it can easily be cleaved.
The generation and reactions of sulfenate anions. An update
Published in Journal of Sulfur Chemistry, 2022
Adam B. Riddell, Matthew R. A. Smith, Adrian L. Schwan
The drive to reduce transition metal catalyzed reactions has prompted the exploration of novel transition metal free sulfenate reactions including arylations and alkenylations/alkynylations [50,110,111]. Recently, Zhang and coworkers [50], Bolm and coworkers [110], and Waser and coworkers [111] published their investigations into the functionalization of sulfenate anions with hypervalent iodine reagents. Hypervalent iodine reagents, in general, are reactive and environmentally benign compounds that tolerate various functional groups and possess low toxicity [110]. These characteristics of hypervalent iodine reagents, such as aryl iodonium salts, make their use in functionalization chemistry more attractive than the traditional transition metal-based protocols reported in this review.
An insight on the different synthetic routes for the facile synthesis of O/S-donor carbamide/thiocarbamide analogs and their miscellaneous pharmacodynamic applications
Published in Journal of Sulfur Chemistry, 2023
Faiza Asghar, Bushra Shakoor, Babar Murtaza, Ian S. Butler
Hypervalent iodine reagents based on their ease of use and minimal toxicity have become popular for a variety of synthetically valuable oxidative reactions in recent years. In Hofmann-type rearrangements, the use of organoiodine compounds as oxidants is particularly significant. PhI(OAc)2 was substituted with iodosylbenzene (PhIO) as an oxidant to minimize the by-product formation. The oxidation of R1CONH2 by PhIO resulted in isocyanate. The nucleophilic attack of amines or alcohols on isocyanate yielded ureas and carbamates [35].