Tertiary propargyl vinyl ethers armed with an electron-withdrawing group (amide or ester) at the tertiary propargylic position have been efficiently transformed into trisubstituted C(2)-chain functionalized furans. The metal-free domino transformation involves a microwave-assisted tandem [3,3]-propargyl Claisen rearrangement/5-exo-dig O-cyclization reaction. The manifold can be performed in a o...

[reaction: see text] Treatment of hydroxy-substituted silyl epoxides with Grignard reagents induces a 1,2-carbon shift to reveal alpha-silyl aldehydes, which are trapped by highly diastereoselective addition reactions of the Grignard reagent. The starting epoxides are readily accessible from propargylic alcohols by regio- and diastereoselective hydrosilylation and epoxidation reactions. In addi...

The first catalytic asymmetric addition of ynamides to aliphatic and aromatic aldehydes is described. This reaction provides unprecedented access to a diverse family of N-substituted propargylic alcohols that are obtained in high yield and ee in the presence of 10 mol% of zinc triflate and N-methylephedrine. The use of apolar solvent mixtures is essential to avoid product racemization and to op...

Here we provide definitive EPR evidence for the existence of α-triphenylstannylvinyl radicals such as (Z)-2 in low temperature O-directed free radical hydrostannation dialkyl propargylic alcohols with Ph3SnH/cat. Et3B and O2 PhMe.

Phosphomolybdic acid (PMA, H3PMo12O40) functioned as a catalyst for reactions of secondary propargylic alcohols and nucleophiles. Highly stable and magnetically recyclable mesoporous silica spheres (MMS) embedded with FeCo-graphitic carbon shell nanocrystals (FeCo/GC@MSS) were fabricated by a modified Stöber process and chemical vapor deposition (CVD) method. The FeCo/GC@MSS were loaded with ph...

Chalcone derivatives are frequently found in bioactive compounds, natural products, and pharmaceuticals. In this study, we developed a KOtBu/DMF catalytic system to efficiently synthesize chalcone by isomerizing propargylic alcohols bearing aryl substituents at the 1- 3-positions. Mechanistic investigations confirmed that 1,3-hydride shift was key process for successful reaction. Our method doe...