Preparation of Tetrasubstituted Furans via Intramolecular Wittig Reactions with Phosphorus Ylides as Intermediates

Abstract

Novel preparation of tetrasubstituted furans, starting from the Michael acceptors, tributylphosphine, and acyl chlorides, is realized. A broad range of highly functional furans can be efficiently generated in one step at room temperature within 10 min to 21 h in moderate to high yields (60-99%). The reaction was proposed to proceed via intramolecular Wittig-type reactions, using phosphorus ylides as intermediates.

Facile Synthesis of Functional Tricyclic Fused Furans by Intramolecular Wittig Reactions

“…To test our proposal, E ‐2‐(4‐nitrobenzylidene)‐1‐tetralone ( 1a ) was chosen as a model substrate. From our previous experience, we quickly established the optimized reaction conditions 10a–10b. Thus, when 1a was treated with 4‐bromobenzoyl chloride ( 2a ; 1.3 equiv.…”

Phosphine‐Catalyzed Reactions with Unsaturated Carbonyl Compounds

“…In 2010, Lin et al reported a one‐step method using tributylphosphine, Michael acceptors 106 , and acyl chlorides 107 to generate highly functionalized furans 108 in moderate to high yields (60%–99%; Scheme ) . The reaction was proposed to proceed through intramolecular Wittig‐type reactions, using phosphorus ylides as intermediates.…”

Diversity‐Oriented Synthesis of Furo[3,2‐c]coumarins and Benzofuranyl Chromenones through Chemoselective Acylation/Wittig Reaction

“…[5] In view of the therapeutic significance of these two species and the fact that the range of heterocyclic libraries is narrowly defined, the development of efficient and concise synthetic methods that fill the chemical space with diverse heterocyclic structures remains an important task in modern organic chemistry. [7] In continuation of our quest towards the chemoselective synthesis of formal crosscoupling adducts and heteroaromatic compounds through Wittig reactions, [8,9] we conceived that the presence of an appropriately positioned hydroxy group on these zwitterions could render two different electrophilic sites after the initial acylation and thus present us with ag reat chance to study ac hemoselective intramolecular Wittig reaction to furnish diverse coumarin skeletons (Scheme 1b). [7] In continuation of our quest towards the chemoselective synthesis of formal crosscoupling adducts and heteroaromatic compounds through Wittig reactions, [8,9] we conceived that the presence of an appropriately positioned hydroxy group on these zwitterions could render two different electrophilic sites after the initial acylation and thus present us with ag reat chance to study ac hemoselective intramolecular Wittig reaction to furnish diverse coumarin skeletons (Scheme 1b).…”

“…[6] Earlier,wereported ageneral method for the preparation of an ew type of highly functional phosphorus zwitterions through at andem three-component reaction of functional alkanes,a ldehydes,a nd Bu 3 Pa nd demonstrated the use of these phosphorus zwitterions in the efficient synthesis of furo [3,2-c]coumarins (Scheme 1a). [7] In continuation of our quest towards the chemoselective synthesis of formal crosscoupling adducts and heteroaromatic compounds through Wittig reactions, [8,9] we conceived that the presence of an appropriately positioned hydroxy group on these zwitterions could render two different electrophilic sites after the initial acylation and thus present us with ag reat chance to study ac hemoselective intramolecular Wittig reaction to furnish diverse coumarin skeletons (Scheme 1b). In this context, we report the diversity-oriented synthesis of two classes of coumarin-based polyheterocycles,f uro [3,2-c]coumarins and benzofuranyl chromenones,from common intermediates.…”