14281-34-6

Upstream product

• 100-52-7 benzaldehyde 
• 825628-12-4 C₁₁H₁₀O 

Downstream Products

• 82084-26-2 5-Benzyl-2,3-dihydro-furan 
• 183584-48-7 Carbonic acid ethyl ester 5-phenyl-penta-3,4-dienyl ester 

Relevant academic research and scientific papers

Enantiodivergent Synthesis of Allenes by Point-to-Axial Chirality Transfer

An enantiodivergent method for the synthesis of multiply substituted allenes is described. Highly enantioenriched, point-chiral boronic esters were synthesized by homologation of α-seleno alkenyl boronic esters with lithiated carbamates and eliminated to form axially chiral allene products. By employing either oxidative or alkylative conditions, both syn and anti elimination could be achieved with complete stereospecificity. The process enables the synthesis of either M or P allenes from a single isomer of a point-chiral precursor and can be employed for the enantioselective assembly of di-, tri-, and tetrasubstituted allenes.

Convenient methods for the synthesis of highly functionalized and naturally occurring chiral allenes

A convenient two step procedure to access highly functionalized chiral allenes using chiral N-methylcamphanyl piperazine derivatives is described. In this transformation, chiral propargylamines are obtained in 79-96% yields with up to 99:1 dr by the CuBr catalyzed reactions of chiral piperazine derivatives with 1-alkynes and aldehydes containing functional groups, which are converted into chiral allenes in the presence of zinc bromide, affording the chiral allenes in 59-85% yields and with up to 99% ee. The antifungal agent Sapium japonicum and an allene precursor intermediate for the synthesis of the pheromone of the male dried bean beetle 15 are obtained in 72-78% yields and with up to 98% ee following this methodology.

1,2,3-triazole bound Au(I) (TA-Au) as chemoselective catalysts in promoting asymmetric synthesis of substituted allenes

The triazole-Au (TA-Au) complexes were identified as effective chemoselective catalysts in promoting propargyl ester/ether 3,3-rearrangements. The highly reactive allenes, which could not be isolated by simple cationic gold catalysts, were prepared in exc

Gold(I)-catalyzed propargyl claisen rearrangement

Homoallenic alcohols are prepared from propargyl vinyl ethers using a trinuclear gold(I)-oxo complex, [(Ph3PAu)3O]BF4, as a catalyst for propargyl Claisen rearrangement at room temperature. The gold(I)-catalyzed reaction is effective for a diverse collection of propargyl vinyl ethers, including substrates containing aryl and alkyl groups at the propargylic position, and hydrogen, aryl, and alkyl substituents at the alkyne terminus. Tertiary propargyl vinyl ethers can be employed in the reaction, at slightly elevated temperatures, to afford tetrasubstituted allenes. Importantly, the rearrangement of 1,2-disubstituted vinyl ethers proceeds with excellent diastereoselectivity, and the rearrangement of chiral nonracemic propargyl vinyl ethers proceeds with excellent chirality transfer to furnish enantioenriched allenes. Copyright

Intramolecular nucleophilic acyl substitution reaction of 3,4-alkadienyl carbonates mediated by Ti(O-i-Pr)4/2 i-PrMgCl reagent. Efficient synthesis of optically active β,γ-unsaturated esters with an α-substituent

Treatment of 3,4-alkadienyl carbonates 2a-i with a low-valent titanium reagent diisopropoxy(η2-propene)titanium (1), readily generated by the reaction of Ti(O-i-Pr)4 with 2 i-PrMgCl, resulted in an intramolecular nucleophilic acyl substitution (INAS) reaction to afford vinyltitanium compounds 3 which, in turn, reacted with H3O+, D2O, or iodine to give α-substituted β,γ-unsaturated esters 4 in good to excellent yields. The olefin moiety of the hydrolysis product 4 has (Z)-geometry mainly except for 4h. Starting from chiral 2f or 2g, the reaction proceeded stereospecifically to give optically active α-substituted β,γ-unsaturated ester 4f or 4g having (Z)-olefin geometry exclusively.