A synthetic method for formyl→ethynyl conversion (RCHO→RCCH or RCCR′)

Aza Cope Rearrangement of Propargyl Enammonium Cations Catalyzed By a Self-Assembled “Nanozyme”

“…Anhydrous solvents were dried over activated alumina under nitrogen pressure and sparged with nitrogen before use. 47 N,N-dimethylisobutenylamine, 48 4-methyl-2-hexynol 49 , and 5-methyl-2-hexynol 50 were prepared according to published procedures.…”

Metal Vinylidenes as Catalytic Species in Organic Reactions

“…[31] The terminal alkyne substrate 44 was prepared by Corey-Fuchs homologation of the commercially available 3-oxopregn-4-ene-20β-carboxaldehyde (43). [32] In this transformation, the enone present in the substrate was effectively protected from side reactions by conversion to the corresponding enolate prior to the reaction. The ruthenium-catalyzed reconstitutive condensation with allyl alcohol (46) then proceeded in good yield to give a mixture of 46 and 47; treatment of this mixture with catalytic rhodium trichloride in aqueous tetrahydrofuran accomplished complete conversion to the α,β-unsaturated ketone 47.…”

Empowering a transition-metal-free coupling between alkyne and alkyl iodide with light in water

“…Research towards the synthesis of alkynes has been pivotal throughout the history of organic chemistry. Methods to synthesize alkyne compounds consist of two types: the first is the direct formation of the triple bond such as the Corey-Fuchs reaction 12 and the SeyferthGilbert homologation 13 ; and the second involves modifications on the basis of a pre-existing triple bond 14,15 . Diverse metalcatalysed alkyne couplings, including the Glaser-Hay coupling, the Cadiot-Chodkiewicz coupling, the Eglinton coupling, the Castro-Stephens coupling and the Sonogashira coupling, have found wide applications in the synthesis of pharmaceuticals, fine chemicals and polymeric materials 14 .…”