Transition-Metal-Free Superbase-Promoted Stereoselective α‑Vinylation of Ketones with Arylacetylenes: A General Strategy for Synthesis of β,γ-Unsaturated Ketones

A wide variety of β,γ-unsaturated ketones of <i>E</i> configuration have been obtained in good to excellent yields via KO^<i>t</i>Bu/DMSO promoted α-vinylation of aliphatic, cycloaliphatic, and alkyl aromatic (heteroaromatic) ketones with diverse arylacetylenes

A One-Pot Approach to Δ²‑Isoxazolines from Ketones and Arylacetylenes

The sequential reaction of ketones with arylacetylenes and hydroxylamine in the presence of KOBu^<i>t</i>/DMSO followed by the treatment of the reaction mixture with H₂O and KOH leads to Δ²-isoxazolines in up to 88% yield

Synthesis of Acyl Terphenyls and Higher Polyaromatics via Base-Promoted C–H Functionalization of Acetylarenes with Arylacetylenes

KO<i>^t</i>Bu/DMSO-promoted C–H functionalization of acetylarenes with arylacetylenes (100 °C, 30 min), generating β,γ-ethylenic ketones, triggers upon further heating (100 °C, 4 h, with or without acidifying additive) the cascade assembly of acyl terphenyls and higher polyaromatics in good yields

Nucleophilic Addition of Ketones To Acetylenes and Allenes: A Quantum-Chemical Insight

A CBS-Q//B3 based study has been carried out to elucidate the mechanism of the KOH/DMSO superbase catalyzed ketones nucleophilic addition to alkyl propargyl and alkyl allenyl ethers yielding, along with (<i>Z</i>)-monoadducts, up to 26% of unexpected (<i>E</i>)-diadducts. The impact of different substrates (alkynes versus allenes) on the reaction mechanism has been discussed in detail. Along with the model reaction of acetone addition to propyne and allene, the addition of acetone and acetophenone to methyl propargyl and methyl allenyl ethers is considered. The limiting reaction stage of the starting ketone carbanion addition to propargyl and allenyl systems occurs with activation energies typical for vinylation of ketones. In contrast, the addition of intermediate α-carbanions to the terminal position of methyl allenyl ether is associated with unusually low activation barriers. The results obtained explain the composition of the reaction products and indicate the participation of mainly the allene form in the reaction