Copper(i) catalyzed synthesis of selanyl methylene 4-chromanol and aurone derivatives

Abstract

An efficient copper-catalyzed cyclization cascade approach towards highly functionalized methylene 4-chromanol and aurone derivatives has been developed from reactions of ynols via 6-exo-dig and 5-exo-dig cyclization respectively.

Recent Approaches in Transition Metal-Catalyzed Chalcogenative Heteroannulation of Alkenes and Alkynes

“…Subsequently, species XVII suffers an intramolecular nucleophilic attack of the neighboring oxygen atom, furnishing 11 and regenerating Cu(I) to the next catalytic cycle (Scheme 19). The same research group developed a mild protocol for the regioselective synthesis of selanilated cromanol 12 and aurone 13 derivatives from homo-propargyl and propargyl alcohols, respectively [49]. The optimal reaction conditions involved the use of CuI (10 mol%) as catalyst, Na2CO3 as the base, and DMF as the solvent resulting in the selanyl methylene 4-chromanol 12 and selanyl aurone 13 products with an up to 96% yield (Scheme 20).…”

Diorganyl Dichalcogenides and Copper/Iron Salts: Versatile Cyclization System To Achieve Carbo- and Heterocycles from Alkynes

“…2) in excellent yields by copper-catalyzed intramolecular cyclization reactions of alkynols in the presence of diorganyl diselenides. 31 Through 6-exo-dig and 5-exo-dig cyclization processes a range of functionalized selenium-containing heterocycles were synthesized with high regioselectivity and stereoselectivity. The reactions were carried out under open to air conditions, using catalytic amounts of CuI, and tolerated a variety of functional groups.…”

“…Eq. 2) were obtained via copper-catalyzed intramolecular cyclization reactions of alkynols in the presence of diorganyl diselenides 31. Through 6exo-dig and 5-exo-dig cyclization processes a range of functionalized selenium-containing heterocycles have been synthesized with high regioselectivity and stereoselectivity.…”

Copper-Catalyzed Cascade Annulation of o-Hydroxyphenyl Propargylamines with Pyrazolin-5-ones to Access Pyrano[2,3-c]pyrazoles

“…Alkynyl o -QMs can originate from two types of precursors, o -hydroxyphenyl propargyl alcohols and o -hydroxyphenyl propargylamines ( o -HPPAs) (Scheme a). Most studies on the chemistry of alkynyl o -QMs so far have been focused on o -hydroxyphenyl propargyl alcohols . In contrast, reactions utilizing o -HPPAs as alkynyl o -QM precursors are relatively limited .…”