RESUMEN
Herein, we report a ligand-controlled palladium-catalyzed method that enables the synthesis of ynones and γ-butenolides with excellent regioselectivity from the same set of readily available aryl iodides, aryl acetylenes, and BrCF2CO2K. In this reaction, the [PdII]âCF2 does demonstrate electrophilicity and can generate CO readily when reacting with H2O. It is environmentally friendly and safe compared to traditional methods, and the current protocol enables us to afford ynones and γ-butenolides in high yields with excellent functionality tolerance. Moreover, esters can also be obtained with corresponding phenols and alcohols utilizing this strategy. The success of late-stage functionalization of bioactive compounds further illustrates the synthetic utility of this protocol in material development and drug discovery.
RESUMEN
Herein, we report a new method of synthesizing of 2-aminobenzofuran 3-enes via the formal C-S insertion reaction of alkyne-tethered diazo compounds. Metal carbene, as a kind of active synthetic intermediate, plays a very important role in organic synthesis. Through the carbene/alkyne metathesis strategy, a new donor carbene is produced in situ as a key intermediate, which has different reactions from the donor receptor carbene.
RESUMEN
A convenient method for the synthesis of fluorine-containing heterocyclic compounds was developed by a copper-catalyzed free radical addition reaction of alkynol and ethyl bromodifluoroacetate. This strategy involves copper-catalyzed free radical addition and molecular lactone exchange of ethynyl alcohol and ethyl bromodifluoroacetate. The method is characterized by easy availability of raw materials, good stereochemical selectivity, and simple operation. More importantly, valuable tetrasubstituted E-configurated alkenes and various vinyl C-Br bonds and difluoromethylene-containing functionalized heterocycles can be obtained by this method.
RESUMEN
We disclose a novel Pd-catalyzed assembly of fluoren-9-ones by merging of C-H activation and difluorocarbene transfer. ClCF2COONa served as a difluorocarbene precursor to be harnessed as a carbonyl source in this transformation. The current protocol enables us to afford fluoren-9-ones in high yields with excellent functional group compatibility, which also represents the first example of using difluorocarbene as a coupling partner in transition-metal-catalyzed C-H activation.
RESUMEN
We report herein an efficient strategy to construct 3-(2,2-difluoroethyl)-2-fluoroindoles from activated o-aminostyrenes with ethyl bromodi-fluoroacetate as a difluorocarbene source. Through double capture of a difluorocarbene, two different types of fluorine motifs are incorporated into the products with simultaneous construction of one C-N and two C-C bonds, without the need for transition metals. This reaction features high efficiency and excellent functional group compatibility and has great potential in the late-stage modifications of pharmaceutical molecules and natural products.
RESUMEN
A convenient and efficient palladium-catalyzed C-H bond activation for the assembly of N-aryl carbazole is reported, in which two C-N bonds were formed under one set of conditions. The desired carbazoles were achieved in decent yields with a wide substrate scope by utilizing readily available 2-iodo biphenyls and aromatic amines as starting materials.