Fe(OTf)3-mediated synthesis of sulfonyl dihydropyrans

A silver-mediated radical process of β-keto sulfones for the synthesis of 2,3-diacyl furans

A facile and efficient method for constructing 2,3-diacyl trisubstituted furans via a silver-mediated radical process of β-keto sulfones is developed. The reaction mechanism has been carefully investigated, revealing that the transformation proceeds through a radical pathway, leading to moderate to good yields of desired products.

One-pot synthesis of sulfonyl dibenzosuberdiones via In(OTf)3-promoted double Friedel-Crafts reactions of oxygenated arylacetic acids with β-arylvinyl sulfones

Under open-vessel atmosphere conditions, a one-pot easy-to-operate method for the construction of diverse sulfonyl dibenzosuberdiones is developed via In(OTf)₃-promoted tandem double Friedel-Crafts reactions of oxygenated arylacetic acids with β-arylvinyl sulfones. A plausible mechanism is proposed and discussed in detail. This protocol allows for highly effective sequential intermolecular Michael addition, intramolecular ring-closure and α-benzylic oxidation via the formation of two carbon-carbon single (C-C) bonds and one carbon-oxygen double (CO) bond.

Iodine-Catalyzed Synthesis of Substituted Furans and Pyrans: Reaction Scope and Mechanistic Insights

Substituted pyrans and furans are core structures found in a wide variety of natural products and biologically active compounds. Herein, we report a practical and mild catalytic method for the synthesis of substituted pyrans and furans using molecular iodine, a simple and inexpensive catalyst. The method described is performed under solvent-free conditions at an ambient temperature and atmosphere, thus offering a facile and practical alternative to currently available reaction protocols. A combination of experimental studies and density functional theory calculations revealed interesting mechanistic insights into this seemingly simple reaction.

Recent advances in the synthesis and applications of β-keto sulfones: new prospects for the synthesis of β-keto thiosulfones

This review mainly focuses on recent developments in the preparation of β-keto sulfones and their extensive synthetic applications. New prospects for the synthesis of β-keto thiosulfones have also been highlighted. Over the last decade, there has been exponential growth in the direct construction of β-keto sulfones using a wide variety of keto and sulfonyl precursors. Of note, the most promising photoredox transformations and electrochemical synthesis methods of β-keto sulfones are also presented. Moreover, β-keto sulfones are versatile building blocks in organic synthesis due to their three essential functional groups: sulfonyl, carbonyl, and active methylene moieties. The convenient preparation of β-keto sulfones allows the synthesis of many valuable carbocyclic and heterocyclic compounds, and the effortless removal of the sulfonyl moiety via transformations is supported. The chemistry of β-keto sulfones (2013 to present) can be divided into several sections based on the sulfonyl surrogates, and ubiquitous synthetic strategies were systematically outlined.

Acid-Controlled Access to β-Sulfenyl Ketones and α,β-Disulfonyl Ketones by Pummerer Reaction of β-Keto Sulfones and Sulfoxides

A convenient acid-mediated reaction of β-keto sulfones with sulfoxides under metal-free conditions has been developed, thereby delivering the acid-controlled synthesis of β-sulfenyl ketones and α,β-disulfonyl ketones in good to excellent yields. The mechanism of the transformations has been studied carefully, which suggested the involvement of a radical process in the formation of α,β-disulfonyl ketones.

In(OTf)3-catalyzed intramolecular hydroarylation of α-phenylallyl β-ketosulfones – synthesis of sulfonyl 1-benzosuberones and 1-tetralones

In(OTf)₃-catalyzed intramolecular hydroarylation of α-phenylallyl β-ketosulfones provides sulfonyl 1-benzosuberones and 1-tetralones in moderate to good yields in refluxing (CH₂Cl)₂ under open-vessel and easy-operation reaction conditions. A plausible mechanism is proposed and discussed. This highly regioselective protocol provides an atom-economic ring-closure route.

In(OTf)₃-catalyzed intramolecular hydroarylation of α-phenylallyl β-ketosulfones provides sulfonyl 1-benzosuberones and 1-tetralones in moderate to good yields in refluxing (CH₂Cl)₂ under open-vessel and easy-operation reaction conditions.

Metal triflate promoted synthesis of naphthalenes

A synthetic route to derive the skeleton of naphthalenes starting with isovanillin is described with modest total yields via the key transformation of metal triflate-mediated intramolecular benzannulation of o-formyl or o-benzoyl allylbenzenes in MeNO₂ at rt.