Herein we report a significant, valuable extension of a recently implemented pyrrole benzannulation methodology that, employing versatile nitrodienes from our lab as useful C building blocks, led to indole derivatives characterized by unusual patterns of substitution. The 6-nitro-7-arylindoles resulting from suitably derivatized, non-symmetric dienes are of foreseeable synthetic interest in search for new polyheterocyclic systems. As an example, pyrrolocarbazoles with a rarely reported ring fusion were synthesized with the classical Cadogan protocol. Furthermore, the proven easy reducibility of the nitro group to amine will surely open the way to further interesting elaborations.
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http://dx.doi.org/10.3390/molecules24203802 | DOI Listing |
J Am Chem Soc
January 2025
State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
The ever-increasing demand in chemical biology and medicinal research requires the development of new synthetic methods for the rapid construction of libraries of heterocycles from simple raw materials. In this context, the utilization of primary amines or HO as the simple - or -sources in the assembly of a heterocyclic ring skeleton is highly desirable from the viewpoint of atom- and step-economy. Herein, we describe a highly efficient three-component reaction of diazo, allylic diacetates, and commercially available anilines (or HO) to access structurally diverse pyrrolidine and tetrahydrofuran derivatives.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Department of Chemistry, College of Sciences, Tianjin University of Science and Technology, Tianjin 300457, People's Republic of China.
A sequential [3 + 2]/[2 + 1] annulation reactions of benzimidazole- and indole-derived acrylonitriles with vinylsulfonium salts have been developed for the first time, and shown to provide in yields of 32 to 98% a series of azabicyclo[3.1.0]hexanes containing each a cyano-substituted tetrasubstituted carbon stereocenter with >20 : 1 dr.
View Article and Find Full Text PDFJ Org Chem
January 2025
College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing, Zhejiang 314001, P. R. China.
An efficient method for construction of various fluorenones has been achieved via Rh(III)-catalyzed C-H activation/[4 + 2] annulation/aromatization sequences of simple and readily available enaminones and 1,3-dienes. This protocol showed good substrate compatibility as an array of structurally and electronically diverse fluorenones prepared efficiently in moderate to good yields and preparative scale utility showing very good efficiency in the late-stage functionalization of complex valuable molecules.
View Article and Find Full Text PDFOrg Lett
December 2024
Hubei Key Laboratory of Natural Products Research and Development, College of Biological and Pharmaceutical Sciences, China Three Gorges University, Yichang, Hubei 443002, China.
An unexpected phosphine-catalyzed controllable three-component domino reaction involving [1 + 2 + 2] annulation and [1 + 2 + 2]/[3 + 2] sequential annulation reaction of 2-arylmethylidene cyanoacetates/malononitriles with Morita-Baylis-Hillman (MBH) carbonates has been developed. A broad range of densely functionalized cyclopentanes and diquinanes bearing five or four consecutive stereogenic centers, including two all-carbon quaternary stereocenters, were smoothly acquired in moderate to excellent yields under mild reaction conditions from readily available materials. Moreover, this divergent transformation enables the simultaneous generation of three or four new C-C bonds and one or two carbocyclic rings in only one step.
View Article and Find Full Text PDFChem Commun (Camb)
December 2024
College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
A palladium-catalyzed divergent reaction of primary benzamides using norbornene (NBE) derivatives as a controlled switch is reported. When NBE is used as a mediator, indanones are synthesized with moderate to good yields a Catellani reaction that involves sequential -C-H alkylation and -C-N bond cleavage annulation of primary benzamides. Employing norbornadiene (NBD) instead of NBE enables the assembly of -alkylamines by an intermolecular hydroamination reaction.
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