Ruthenium-catalyzed formation of pyrazoles or 3-hydroxynitriles from propargyl alcohols and hydrazines
作者:Julia Kaufmann、Elisabeth Jäckel、Edgar Haak
DOI:10.24820/ark.5550190.p010.893
日期:——
Functionalized pyrazoles are generated from secondary propragyl alcohols and hydrazines in a rutheniumcatalyzed cascade process, consisting of redox isomerization, Michael addition, cyclocondensation and dehydrogenation steps. The same bifunctional catalyst mediates the conversion of tertiary propargyl alcohols with hydrazine to 3-hydroxynitriles via anti-Markovnikov hydroamination followed by elimination
palladium-catalyzed rearrangement of bis-allylic acetates 4 and 5 and the second one is based on the stereoselective reduction of homopropargylic alcohols 6 followed by an elimination reaction. These stable chlorotrienes 1–3 are suitable synthetic intermediates for the construction of navenone B and allE polyenes (trienes, tetraenes, hexaenes and heptaenes).
5-Exo-dig aminocylization/hydroxyfluorination of propargylic carbamates
作者:Antonio Arcadi、Marco Chiarini、Luana Del Vecchio、Fabio Marinelli
DOI:10.1016/j.jfluchem.2018.04.002
日期:2018.7
The reaction was effectively promoted by NaHCO3 and/or silver catalysis. The peculiar behavior of propargylic carbamates bearing a chiral steroidal moiety is described. Extensions and limitations of the procedure with respect to urea derivatives, homopropargyl compounds, internal alkynes and one-pottransformations of propargylic alcohols with isocyanates are reported.
High molecular weight polyacetylenes from the nudibranch Peltodoris actromaculata and the sponge Petrosia ficiformis
作者:D. Castiello、G. Cimino、S. De Rosa、S. De Stefano、G. Sodano
DOI:10.1016/s0040-4039(00)71129-4
日期:1980.1
Two series of high molecular weight straight chain polyacetylenes (C46, C49 and C49, C52, C55) have been isolated from two marine invertebrates and partially characterized.