Alkynoates as a Source of Reactive Alkylinides for Aldehyde Addition Reactions

Abstract

[see reaction]. The reaction of activated alkynes with carbonyl compounds in the presence of a catalytic amount of a nucleophile leads to enol-protected functionalized propargyl alcohols and 1,3-dioxolane compounds by way of a mild carbon-carbon bond formation reaction.

Propargyl Claisen rearrangement: allene synthesis and beyond

“…1). It must be added at this point that PVEs with this type of vinyl substitution pattern can also be accessed directly from alkyl propiolates and aldehydes in a very straightforward manner if R 1 = CO 2 R. 22 When using a terminal alkyl propiolate, triethylamine seems to be the most convenient catalyst for the reaction, and the PVEs are synthesised in high yields and short periods of time at room temperature (R 4 = H, Fig. 1).…”

Chemo-differentiating ABB′ multicomponent reactions. Privileged building blocks

“…Depending on the catalyst and the reaction conditions, one molecule of an aliphatic aldehyde or certain -dicarbonyl compounds and two molecules of a 165 terminal conjugated alkynoate may be combined to yield enolprotected propargylic alcohols 6 (Scheme 3) or 1,2-dihydrofuran derivatives 12 (Scheme 4). 15,16 Both processes represent examples of ABB' 3CRs and have a common starting point. The energetically favoured 170 nucleophilic addition on the terminal conjugated alkyne generates the zwitterionic allenolate 7, which deprotonates the starting conjugated alkyne to generate the reactive acetylide salt 8.…”

Chemo‐Differentiating ABB′ Multicomponent Reactions: Privileged Building Blocks

“…Depending on the catalyst and the reaction conditions, one molecule of an aliphatic aldehyde or certain -dicarbonyl compounds and two molecules of a terminal conjugated alkynoate may be combined to yield enolprotected propargylic alcohols 6 (Scheme 3) or 1,2dihydrofuran derivatives 12 (Scheme 4). 15,16 Both processes represent examples of ABB' 3CRs and have a common starting point. The energetically favoured nucleophilic addition on the terminal conjugated alkyne generates the zwitterionic allenolate 7, which deprotonates the starting conjugated alkyne to generate the reactive acetylide salt 8.…”