4 research outputs found
Decorated Cyclopentadienes from Acetylene and Ketones in Just Two Steps
The products of the
one-pot assembly of acetylene and ketones in
the KOH/DMSO system, 7-methylene-6,8-dioxabicyclo[3.2.1]octanes,
undergo an acid-catalyzed (CF<sub>3</sub>COOH, room temperature) rearrangement
to rarely substituted cyclopentadienes in good-to-excellent
yields. The mechanism of the rearrangement has been supported by the
isolation and corresponding transformations of two intermediates
Regioselective N(2)-H-functionalization of thiosemicarbazones of aromatic and heteroaromatic aldehydes with acrylonitrile
<p>Regioselective N(2)-H-cyanoethylation of thiosemicarbazones of aromatic and heteroaromatic aldehydes with acrylonitrile proceeds under mild conditions (14% KOH, acetone/H<sub>2</sub>O, 35 °C, 6–21 h) to afford 1-(2-сyanoethyl)-2-[(<i>E</i>)-aryl(heteroaryl)methylidene]-1-hydrazinecarbothioamides in up to 74% yields. The synthesized thioamides are promising precursors of novel families of functionalized thiosemicarbazones as exemplified by hydrolysis of their cyano group to the corresponding amido function (46.5–60% yields).</p
Domino Assembly of Trifluoromethylated N,O-Heterocycles by the Reaction of Fluorinated α‑Bromoenones with Amino Alcohols
A highly efficient
method for the selective synthesis of trifluoromethylated
morpholines (4-oxa-1-azabicyclo[4.1.0]heptanes) and so far unknown
1,4-oxazepanes (2,8-dioxa-5-azabicyclo[5.1.0]octanes) based on a domino
reaction of fluorinated α-bromoenones with β-amino alcohols
was elaborated. The assembly of both heterocyclic systems is initiated
by an aza-Michael reaction followed by intramolecular cyclization.
The conditions for total control of selectivity of the reaction were
found
Synthesis of Acyl Terphenyls and Higher Polyaromatics via Base-Promoted C–H Functionalization of Acetylarenes with Arylacetylenes
KO<i><sup>t</sup></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