The ruthenium-catalyzed Fujiwara-Moritani reaction (oxidative-Heck reaction) of Weinreb amides is reported herein. The reaction affords exclusively ortho-C-H olefination products, has excellent substrate scope and tolerates halogen functionalities, which increase the synthetic utility of the method. A variety of activated olefins as well as styrenes can be employed as coupling partners.
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http://dx.doi.org/10.1002/asia.201500343 | DOI Listing |
Dalton Trans
May 2023
Indian Institute of Technology, Powai, Mumbai, 400076, India.
Dipyrromethenes containing two pyrrole rings connected by one -carbon are versatile monoanionic bidentate ligands and form coordination complexes with many metals/nonmetals/metalloids. Dipyrroethenes containing one additional -carbon compared to dipyrromethenes have more space between coordinating pyrrole nitrogens and provide a good coordination environment but have not been explored as ligands in coordination chemistry. Dipyrroethenes are dianionic bidentate ligands and by suitable modifications, the coordination environment of dipyrroethenes can be changed further.
View Article and Find Full Text PDFHerein we report, a rhodium-catalyzed Fujiwara-Moritani-type reaction of unactivated terminal alkenes and benzoic acid derivatives bearing electron donating residues under mild conditions. The acid functionality acts as a traceless directing group delivering products alkenylated in -position to the electron donating substituent in contrast to the usually obtained - and -substitution in Friedel-Crafts-type reactions. Remarkably, the new C-C bond is formed to the C2 of the terminal olefin, in contrast to similar reported transformations.
View Article and Find Full Text PDFJ Am Chem Soc
November 2022
Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
C-H/C-H coupling via C-H activation provides straightforward synthetic access to the construction of complex π-conjugated organic molecules. The palladium-catalyzed Fujiwara-Moritani (FM) coupling between an arene and an electron-deficient olefin presents an early example but is not applicable to enamines such as -vinylcarbazoles and -vinylindoles. We report herein iron-catalyzed C-H/C-H heterocoupling between enamines and thiophenes and its application to copolymerization of bisenamine and bisthiophene using diethyl oxalate as an oxidant and AlMe as a base, as a result of our realization that synthetic limitations in oxidative C-H/C-H couplings imposed by the high redox potential of the Pd(II)/Pd(0) catalytic cycle can be circumvented by the use of iron, which has a lower Fe(III)/Fe(I) redox potential.
View Article and Find Full Text PDFChem Sci
August 2022
IIT Bombay, Department of Chemistry and IDP, Climate Studies Powai Mumbai 400076 India
The Fujiwara-Moritani reaction is a powerful tool for the olefination of arenes by Pd-catalysed C-H activation. However, the need for superstoichiometric amounts of toxic chemical oxidants makes the reaction unattractive from an environmental and atom-economical view. Herein, we report the first non-directed and regioselective olefination of simple arenes an electrooxidative Fujiwara-Moritani reaction.
View Article and Find Full Text PDFJ Am Chem Soc
February 2022
Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
The Fujiwara-Moritani reaction has had a profound contribution in the emergence of contemporary C-H activation protocols. Despite the applicability of the traditional approach in different fields, the associated reactivity and regioselectivity issues had rendered it redundant. The revival of this exemplary reaction requires the development of a mechanistic paradigm that would have simultaneous control on both the reactivity and regioselectivity.
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