One-pot synthesis of tri- and di-fluoromethylated bis(indolyl)methanols via Friedel-Crafts-type acylation and alkylation.

A simple and efficient methodology for the first synthesis of tri- and di-fluoromethyl-bis(indolyl)methanols has been demonstrated through a one-pot Friedel-Crafts-type acylation-alkylation of readily available indoles and fluorinated acids. This simple protocol was successfully performed under metal-, additive-, toxic-solvent-, and protective-gas-free conditions, and delivered a wide range of tri- and di-fluoromethyl-bis(indolyl)methanols in moderate to high yields. Notably, this reaction can tolerate diverse vital and reactive functional groups. Furthermore, this one-pot Friedel-Crafts-type acylation-alkylation can be readily expanded to the gram scale with no obvious decrease in the yield, demonstrating its high application potential.

Substrate-Controlled Regiodivergent Synthesis of Fluoroacylated Carbazoles via Friedel-Crafts Acylation.

A general, efficient, and substrate-controlled regiodivergent trifluoroacetylation of carbazoles has been developed through Friedel-Crafts acylation. This strategy was applicable to a wide scope of readily available substituted carbazoles at air atmosphere without using a metal catalyst, affording the corresponding trifluoroacetylated carbazoles in up to 99% yield. The divergency of the products and the orientation rules have been illustrated based on different substituents on carbazole rings. This method could also be extended to the synthesis of chlorodifluoroacetylated and pentafluoropropionylated carbazoles, which have been achieved for the first time.

Fe(OTf)3- and γ-Cyclodextrin-Catalyzed Hydroamination of Alkenes with Carbazoles.

A Fe(OTf)3- and γ-cyclodextrin catalyzed hydroamination of alkenes with carbazoles is demonstrated. This biomimetic-catalyst-oriented sustainable and green method could deliver a wide scope of N-alkylated carbazoles and N-alkylated-carbazole-fused aromatics in up to 97% yield. The salient features of this transformation include simple and benign reaction conditions with no need for a strong base, additive, or the irradiation of light.

Iron-catalyzed alkylation of carbazole derivatives via hydroarylation of styrenes.

The first direct and selective 3,6-di-alkylation of carbazoles via iron-catalyzed hydroarylation of styrenes is demonstrated. This simple, general and efficient method could deliver a wide range of di-benzyl-carbazoles with high chemo- and regio-selectivity at room temperature in up to 96% yield with no need for a noble-metal catalyst, directing group or additives.

An Ionic Liquid on a Porous Organic Framework Support: A Recyclable Catalyst for the Knoevenagel Condensation in an Aqueous System.

Porous aromatic frameworks (PAFs) that feature a high density of phenyl rings in their robust frameworks are attractive platforms for catalysis because of their extremely high stability, high surface area, and adjustable pore size. In this paper, two PAF-supported ionic liquids were constructed by introducing ionic liquid units onto the framework of a PAF material PAF-111 using a series of stepwise post-synthetic modifications. The basic PAF-supported ionic liquid with a hydroxy anion exhibited high catalytic activity and high stability, and could undergo at least 10 cycles without any activity loss when catalyzing Knoevenagel condensation reaction under aqueous conditions. It is expected that our study will further promote the development of designing and applying functional PAF materials for catalysis in aqueous systems.