Palladium(II)-Catalyzed Direct C–H Alkenylation of Thienothiophene and Related Fused Heteroarenes

The palladium-catalyzed direct alkenylation of thieno­[3,2-<i>b</i>]­thiophene takes place regioselectively at C2. Symmetrically and unsymmetrically 2,5-dialkenylated thienothiophene derivatives can be prepared by the catalytic procedure. Related fused thienyl and carbazole derivatives also undergo regioselective direct alkenylation

Correction to Iridium-Catalyzed Annulative Coupling of 2‑Arylbenzoyl Chlorides with Alkynes: Selective Formation of Phenanthrene Derivatives

Correction to Iridium-Catalyzed Annulative Coupling of 2‑Arylbenzoyl Chlorides with Alkynes: Selective Formation of Phenanthrene Derivative

Copper-Mediated Dehydrogenative Biaryl Coupling of Naphthylamines and 1,3-Azoles

A copper-mediated dehydrogenative biaryl cross-coupling of naphthylamines and 1,3-azoles has been developed. The key to its success is the introduction of N,N-bidentate coordination system based on the picolinamide directing group. The reaction proceeds smoothly without precious transition metal catalysts and provides highly π-extended heterobiaryls directly

Synthesis of Difluorinated Enynes through Sonogashira-Type Coupling

The Sonogashira-type coupling of 2,2-difluoroethenyl tosylate with a variety of aliphatic and aromatic terminal alkynes proceeds smoothly even at room temperature to produce the corresponding difluorinated enyne derivatives. 2,2-Difluoroethenyl tosylate is a useful difluoroethenyl source because of its ready availability from 2,2,2-trifluoroethanol. Some of the obtained enynes exhibit strong fluorescence in the solid state. Further derivatization of a difluorinated enyne through Rh­(III)-catalyzed oxidative coupling has also been examined

Copper-Mediated Formally Dehydrative Biaryl Coupling of Azine <i>N</i>‑Oxides and Oxazoles

A copper-mediated formally dehydrative biaryl coupling of azine <i>N</i>-oxides and oxazoles has been developed. The C–C bond-forming process proceeds, accompanied by the removal of the oxygen atom from the azine core, to directly afford the azine–oxazole biaryl linkage. Moreover, this system requires no noble transition metals such as palladium and rhodium, which are common promotors in the related dehydrogenative couplings with the azine <i>N</i>-oxide. Thus, the present protocol can provide a unique and less expensive approach to the azine-containing biheteroaryls of substantial interest in pharmaceutical and medicinal chemistry

Copper-Catalyzed Enantioselective Formal Hydroamination of Oxa- and Azabicyclic Alkenes with Hydrosilanes and Hydroxylamines

A CuCl/(<i>R,R</i>)-Ph-BPE-catalyzed enantioselective formal hydroamination of oxa- and azabicyclic alkenes with polymethylhydrosiloxane (PMHS) and <i>O</i>-benzoylhydroxylamines has been developed. The efficient and stereoselective net addition of hydrogen and nitrogen atoms provides the corresponding optically active oxa- and azanorbornenyl- and -norbornanylamines in good yields and good enantiomeric ratios

Synthesis of <i>N</i>‑Vinylcarbazoles via Dehydrogenative Coupling of <i>N</i>‑H Carbazoles with Alkenes under Palladium Catalysis

The synthesis of <i>N</i>-vinylcarbazoles was achieved by the palladium-catalyzed aza-Wacker reaction of <i>N</i>-H carbazoles with styrenes. In this reaction, Markovnikov adducts were exclusively produced. In contrast, the reaction with electron-deficient alkenes such as acrylates and acrylamides gave only anti-Markovnikov adducts

Ruthenium-Catalyzed Regioselective C–H Alkenylation Directed by a Free Amino Group

The ruthenium-catalyzed alkenylation reactions of 2-aminobiphenyls and cumylamine proceed smoothly to produce the corresponding regioselectively alkenylated products. These reactions involve a C–H bond cleavage directed by their free amino groups

Copper-Mediated Formally Dehydrative Biaryl Coupling of Azine <i>N</i>‑Oxides and Oxazoles

A copper-mediated formally dehydrative biaryl coupling of azine <i>N</i>-oxides and oxazoles has been developed. The C–C bond-forming process proceeds, accompanied by the removal of the oxygen atom from the azine core, to directly afford the azine–oxazole biaryl linkage. Moreover, this system requires no noble transition metals such as palladium and rhodium, which are common promotors in the related dehydrogenative couplings with the azine <i>N</i>-oxide. Thus, the present protocol can provide a unique and less expensive approach to the azine-containing biheteroaryls of substantial interest in pharmaceutical and medicinal chemistry