9 research outputs found
Palladium-Catalyzed Domino Cyclization/Alkylation of Terminal Alkynes: Synthesis of Alkynyl-Functionalized Azaindoline Derivatives
A novel
palladium-catalyzed domino cyclization/alkylation of terminal alkynes
was achieved for the synthesis of alkynyl-functionalized 3,3-disubstituted
azaindoline derivatives under air atmosphere conditions. Various types
of terminal alkynes, including aromatic alkynes, aliphatic alkynes,
and ferrocene acetylene, can undergo the process successfully. The
protocol provides a range of alkynyl-functionalized azaindoline scaffolds
bearing a quarternary carbon center
Palladium-Catalyzed Domino Heck/Intermolecular C–H Bond Functionalization: Efficient Synthesis of Alkylated Polyfluoroarene Derivatives
An
efficient palladium-catalyzed alkylation of electron-deficient
polyfluoroarenes is described. The protocol provides a useful and
operationally simple access to a broad scope of alkylated polyfluoroarene
derivatives in moderate to excellent yields. This also represents
the first example of the introduction of a polyfluoroarene structure
involving an alkylpalladiumÂ(II) intermediate
Palladium-Catalyzed Domino Heck/Intermolecular C–H Bond Functionalization: Efficient Synthesis of Alkylated Polyfluoroarene Derivatives
An
efficient palladium-catalyzed alkylation of electron-deficient
polyfluoroarenes is described. The protocol provides a useful and
operationally simple access to a broad scope of alkylated polyfluoroarene
derivatives in moderate to excellent yields. This also represents
the first example of the introduction of a polyfluoroarene structure
involving an alkylpalladiumÂ(II) intermediate
Palladium-Catalyzed Intramolecular Dearomatization of Indoles via Decarboxylative Alkynyl Termination
A highly
diastereoselective dearomatization of indoles via palladium-catalyzed
decarboxylative alkynyl termination was developed. This protocol provides
dissimilar tetracyclic and tetrasubstituted indoline scaffolds bearing
congested stereocenters, which led to operationally simple conditions,
short time, and broad substrate scope. Additionally, this reaction
system could be scaled to gram quantities in a satisfactory yield
and diastereoselectivity
Palladium-Catalyzed Domino Heck/Intermolecular C–H Bond Functionalization: Efficient Synthesis of Alkylated Polyfluoroarene Derivatives
An
efficient palladium-catalyzed alkylation of electron-deficient
polyfluoroarenes is described. The protocol provides a useful and
operationally simple access to a broad scope of alkylated polyfluoroarene
derivatives in moderate to excellent yields. This also represents
the first example of the introduction of a polyfluoroarene structure
involving an alkylpalladiumÂ(II) intermediate
Palladium-Catalyzed Radical Cascade Iododifluoromethylation/Cyclization of 1,6-Enynes with Ethyl Difluoroiodoacetate
A novel and convenient Pd-catalyzed
radical cascade iododifluoromethylation/cyclization
of 1,6-enynes with ethyl difluoroiodoacetate is demonstrated. The
proposed transformation presents high stereoselectivity under mild
and facile reaction conditions, thereby allowing an efficient access
to a variety of iodine-containing difluoromethylated pyrrolidines.
A possible radical pathway for the transformation is proposed on the
basis of the results of control experiments and relevant literature
reviews
Lewis Acid Mediated Tandem Reaction of Propargylic Alcohols with Hydroxylamine Hydrochloride To Give α,β-Unsaturated Amides and Alkenyl Nitriles
We
have developed a highly selective method for the synthesis of
α,β-unsaturated amides and alkenyl nitriles from readily
available propargylic alcohols. The reaction proceeded smoothly under
the neutral conditions with hydroxylamine hydrochloride (NH<sub>2</sub>OH·HCl) as the nitrogen source. The development of these new
strategies has significantly extended the application of hydroxylamine
hydrochloride to the chemistry of propargylic alcohols. Moreover,
both secondary and tertiary alcohols have been highly regioselectively
transformed to the desired products with good functional group compatibility
Silver-Catalyzed Oxidative Cyclization of Propargylamide-Substituted Indoles: Synthesis of Phosphorated Indoloazepinones Derivatives
A silver-catalyzed
oxidative cyclization of 2- or 3-propargylamide-substituted
indoles to synthesize phosphorated indoloazeÂpinone derivatives
is described. This reaction displays a difunctionalizalion of alkynes
with diphenylÂphosphine oxides to construct a seven-membered
ring through a radical cyclization process. The indoloÂazepinones
derivatives are common structural motifs found in many natural products
and pharmaceuticals
Facile Synthesis of Disubstituted Isoxazoles from Homopropargylic Alcohol via Cî—»N Bond Formation
A novel
iron-catalyzed aerobic oxidative reaction to synthesize
disubstituted isoxazoles from homopropargylic alcohol, <i>t</i>-BuONO, and H<sub>2</sub>O is developed. The method provides mild
conditions to afford a variety of useful substituted heterocycles
in an efficient and regioselective manner. The mechanism has been
studied and proposed, which indicates that the transformation can
be realized through construction of a Cî—»N bond and Cî—»O
bond, C–H oxidation, and then cyclization. Moreover, this method
can be enlarged to gram scale