Iodine as a mild and versatile reagent for the synthesis of 1,3-dioxane derivatives via the Prins reaction

Metal-free synthesis of 1,3-dioxane derivatives from aromatic alkynes and paraformaldehyde

Here we report the efficient synthesis of a series of 1,3-dioxane derivatives from aromatic alkynes, paraformaldehyde and a Lewis acid-catalyzed reaction at room temperature. This reaction is metal-free and atom-economic. Single crystals of two typical 1,3-dioxane derivatives are obtained. A mechanism that the reaction is do through a six or eight-membered ring intermediate is proposed

The Catalytic Asymmetric Intermolecular Prins Reaction

Despite their significant potential, catalytic asymmetric reactions of olefins with formaldehyde are rare and metal-free approaches have not been previously disclosed. Here we describe an enantioselective intermolecular Prins reaction of styrenes and paraformaldehyde to form 1,3-dioxanes, using confined imino-imidodiphosphate (iIDP) Brønsted acid catalysts. Isotope labeling experiments and computations suggest a concerted, highly asynchronous addition of an acid-activated formaldehyde oligomer to the olefin. The enantioenriched 1,3-dioxanes can be transformed into the corresponding optically active 1,3-diols, which are valuable synthetic building blocks.

Recent Progress in Vibropolaritonic Chemistry

Vibrational polaritonic chemistry is emerging as an exciting new sub-field of chemistry, one in which strong interactions with optical cavity vacuum fields are another degree of freedom alongside temperature, solvent, catalyst, and so on to modify thermochemical reactivity. The field stands at a fascinating juncture with experimental works on a variety of organic reactions continuing to blossom, just as many theoretical works appear which diverge significantly in their predictions compared to experiments. The outlook for the field is no doubt an exciting one as it seeks to unify the observed novel optical cavity-induced chemical phenomena with satisfying accompanying physical theory. In this minireview we highlight experimental works on vibrational polaritonic chemistry that have appeared most recently, focusing on the chemistry of the rate-limiting steps to provide mechanistic insight. We hope this review will encourage synthetic chemists to enter the field and we discuss the opportunities and challenges that lie ahead as polaritonic chemistry grows into the future.

Synthesis and investigation of new cyclic molecules using the stilbene scaffold

A new approach to the synthesis of asymmetrical cyclic compounds using a stilbene scaffold has been developed. The use of boron trifluoride diethyl etherate as the catalyst, both with and without paraformaldehyde, allows us to obtain new substituted dioxanes, oxanes, cyclic compounds or dimer. The analysis of products was run using experimental and theoretical methods.

A new approach to the synthesis of asymmetrical cyclic compounds using a stilbene scaffold has been developed.

Iodine-catalyzed efficient synthesis of chalcones by grinding under solvent-free conditions

Chalcones are useful intermediates in organic synthesis and exhibit a large number of different biological activities. Chalcones have been synthesized in high yields by Claisen–Schmidt condensation of substituted acetophenones with various aromatic aldehydes in the presence of 10 mol% of iodine at room temperature by grinding under solvent-free conditions.

Iodine catalysed synthesis of 5-(arylmethylidene)rhodanines by Grinding under Solvent-Free Conditions

5-(Arylmethylidene)rhodanines have been synthesised in 88–95% yields by Knoevenagel condensation of various aromatic aldehydes with rhodanine in the presence of a catalytic amount of iodine at room temperature by grinding under solvent-free conditions.