Solvent free, phosphine free Pd-catalyzed annulations of aryl bromides with diarylacetylenes

Effect of Cp‐Ligand Methylation on Rhodium(III)‐Catalyzed Annulations of Aromatic Carboxylic Acids with Alkynes: Synthesis of Isocoumarins and PAHs for Organic Light‐Emitting Devices

“…6‐Methoxy‐1,2,3,4‐tetraphenylnaphthalene (2 e) : yellow solid; SiO 2 , petroleum ether/dichloromethane (10 : 1); 1 H NMR (CDCl 3 ): δ =3.75 (s, 3H, OMe), 6.90–6.95 (m, 10H), 7.05 (s, 1H), 7.15 (d, 1H, J =9.1 Hz), 7.29–7.34 (m, 10H), 7.67 (d, 1H, J =9.1 Hz) ppm (cf …”

“…[27] ). [27] ). General procedure for the oxidative coupling of carboxylic acids with internal alkynes catalyzed by mixture Cp*H/RhCl 3 : A mixture of carboxylic acid (0.5 mmol), alkyne (1.1 mmol), Cp*H (10 μl, 0.06 mmol), RhCl 3 (2.1 mg, 0.01 mmol), Cu(OAc) 2 · 2H 2 O (436 mg, 2.00 mmol) and o-xylene (2 ml) was refluxed with vigorous stirring for 6 h. Isolation and purification of products were carried out as described above.…”

Microwave‐assisted Three‐component Reactions for Regioselective Synthesis of Functionalized Benzo[e]indoles

“…Over the past years, the synthesis of 3 H ‐benzo[ e ]indoles has been attracted considerable attentions because of their significance in pharmaceuticals and organic materials. A survey of the literature shows that five general strategies have been reported including thermal rearrangement of 4,5‐dihydro‐1 H ‐benzo[ g ]indoles , intramolecular electrophilic cyclization of o ‐ethynylphenyl substituted pyrroles , benzannulation of suitable indole skeletons, pyrrole annulation of naphthalene‐type precursors , and p ‐TsOH‐catalyzed cyclization of α‐keto imines with 1,3‐dicarbonyls . The former three procedures often require multiple steps, narrow substrate scope, or harsh reaction conditions whereas the latter allow direct formation of pyrroles and their efficient multifunctionalization in particular and thus represent a highly desirable methodology.…”

Assembly of Indole Cores through a Palladium-Catalyzed Metathesis of Ar–X σ-Bonds

“…The advancement of a controlled ligand exchange in a palladium-catalyzed carbopalladation/annulation/amination cascade for the construction of indole core, however, would encounter challenges via some probable side reactions. Classical Larock indole synthesis via the assembly of amines and alkynes, Buchwald–Hartwig amination of iodoarenes for the construction of diaryl amines, and the assembly of alkyne and arenes for the construction of various carbocycles are some competing paths in case. Suppressing the side oxidative addition of iodoarene to palladium(0) and the alkyne carbopalladation reaction is a further challenge …”