Palladium‐Catalyzed Suzuki Coupling with Terminal Alkynes – Application to the Synthesis of 2,3‐Disubstituted Benzo[b]furans

Abstract

The Suzuki coupling reaction between alkynylboronic esters (generated in situ from acetylenic derivatives) and aryl bromides, pyridyl bromides or vinyl bromides is reported. 5-endo-dig-iodocyclisation of o-alkynylanisoles, generated by this palladium-catalyzed Suzuki coupling reaction, was performed with N-iodosuccinimide (NIS) in the presence of

Transition metals in organic synthesis: Highlights for the year 2005

“…Suzuki couplings of potassium alkyl-, aryl-, alkynyl-, and alkenyltrifluoroborates [23,[257][258][259][260][261][262], potassium triethyl 2-indolylborate [263], and lithium alkynyltriisopropoxyborates [264] were described. Alkenyl tellurides were coupled with alkynyltrifluoroborates [265].…”

A Simple and Efficient Synthesis of 2,3-Diarylnaphthofurans Using Sequential Hydroarylation/Heck Oxyarylation

“…17 Since then transition metal catalyzed coupling/ cyclization of suitably functionalized alkynes as starting materials has been focus for the synthesis of 2,3-diarylbenzofurans and 2,3-diarylnaphthofurans. [18][19][20][21] A number of methods have been developed for synthesis of 2,3-diarylbenzofurans but synthetic routes for naphthofurans are limited, 11,14 and synthesis of diversified naphthofurans still presents major challenge in organic synthesis.…”

Preparation of the metabotropic glutamate receptor 5 (mGluR5) PET tracer [ 18 F]FPEB for human use: An automated radiosynthesis and a novel one-pot synthesis of its radiolabeling precursor

“…Hence, we also sought to develop a simpler and more efficient method for the synthesis of the nitrobenzonitrile precursor and the authentic standard FPEB. Colobert et al recently reported a methodology of palladium-catalyzed Suzuki-like sp-sp2 coupling of aryl halides with terminal alkynes for the synthesis of 2,3-disubstituted benzo[ b ]furans, by first deprotonating the alkynes with n -butyl lithium to form an alkynyllithium and then reacting with triisopropylborate to generate a lithiated boronate complex in situ, followed by Pd-catalyzed coupling with arylbromides (Castanet et al, 2000; Colobert et al, 2005). We adopted this methodology for an efficient, one-pot preparation of FPEB and its nitrobenzonitrile radiolabeling precursor from commercially available building blocks.…”