An efficient and expeditious synthesis of novel 2,2-dialkyl-2,3-dihydrobenzofurans from phenols and 2,2-dialkylacetaldehydes

Synthesis of naphthodihydrofurans via an iron(iii)-catalyzed reduction radical cascade reaction

A convenient method for the synthesis of naphthodihydrofurans has been developed by iron(iii)-catalyzed cascade reaction of reducing radicals.

Dihydronaphthofurans: synthetic strategies and applications

Dihydronaphthofurans (DHNs) are an important class of arene ring-fused furans which are widely found in many natural and non-natural products and drug candidates with relevant biological and pharmacological activities. Furthermore, vinylidene-naphthofurans exhibit photochromic properties when exposed to UV or sun light at room temperature. For these reasons, a vast array of synthetic procedures for the preparation of dihydronaphthofurans including annulation of naphthols with various reagents, cycloaddition reactions ([3 + 2], [4 + 1] and Diels-Alder), intramolecular transannulation, Friedel-Crafts, Wittig, Claisen rearrangement, neophyl rearrangement and other reactions under various conditions have been developed over the past decades. This review aims to describe the different strategies developed so far for the synthesis of dihydronaphthofurans and their applications. After a brief introduction to the types of dihydronaphthofurans and their biological activities, the different synthetic approaches such as chemical, photochemical, and electrochemical, methods are described and organized on the basis of the catalysts and the other reagents employed in the syntheses. The subsequent section focuses on biological and pharmacological applications and photochromic properties of the target compounds.

Synthesis of hydrazinoheterocycles from Morita–Baylis–Hillman adducts of nitroalkenes with azodicarboxylates

Hydrazinonitroalkenes derived from nitroalkenes and azodicarboxylates are excellent substrates for the synthesis of hitherto unreported hydrazinotriazoles and hydrazinodihydrofurans.

Aza-Diels-Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

The synthesis of 5-substituted 6,6a-dihydroisoindolo[2,1-a]quinolin-11(5H)-ones via [4 + 2] imino-Diels-Alder cyclization from N-aryl-3-hydroxyisoindolinones and N-vinyl lactams under Lewis acid-catalysed anhydrous conditions is reported. Reactions of N-(2-substituted-aryl)-3-hydroxyisoindolinones with N-vinylpyrrolidone under identical conditions resulted in the formation of 2-(2-substitued-aryl)-3-(2-(2-oxopyrrolidin-1-yl)vinyl)isoindolin-1-one analogues indicating steric hinderance as the cause of deviation. The probable mechanism of the reaction based on the results from X-ray crystallography and molecular modelling is discussed.