Selective synthesis of 2,5-disubstituted furan-3-carboxylates and the isomeric 2,4-disubstituted furan-3-carboxylates

Abstract

Regioselective formation of 2,5-disubstituted furan-3-carboxylates and the isomeric 2,4-disubstituted furan-3-carboxylates from the same substrates was realized under different reaction condition.

Base‐Mediated N‐Arylation for the Synthesis of 9H‐Pyrrolo[1,2‐a]indol‐9‐ones and 10H‐Indolo[1,2‐a]indol‐10‐ones

“…(2-Bromophenyl)(1H-pyrrol-2-yl)methanone (1a) was used as substrate for the optimization of reaction conditions. Based on our previous studies regarding the transition metal free CÀ N bond formation, [37,38] 1a was initially treated with Cs 2 CO 3 in DMF at 125°C. Upon completion (12 h), fluorazone 2a was isolated in 91 % yield ( Table 1, Entry 1).…”

“…[32 -34] Recently, we have become interested in base-mediated CÀ N and CÀ O bond formation for the synthesis of heterocyclic compounds. [37][38][39][40] This motivated us to develop an efficient and practical transition-metal-free intramolecular N-arylation protocol to access fluorazones and analogues.…”

Understanding the Scope of Feist–Bénary Furan Synthesis: Chemoselectivity and Diastereoselectivity of the Reaction Between α‐Halo Ketones and β‐Dicarbonyl Compounds

“…Ethyl 2,5‐Dimethylfuran‐3‐carboxylate (VIa): To 500 mg of ethyl 2‐acetyl‐4‐oxopentanoate (V a) was added two drops of concentrated sulfuric acid. The mixture was stirred at 80 °C for 1 h until it turned to black.…”

Base‐Promoted Cycloisomerization for the Synthesis of Indolizines and Related Heterocycles

“…However, halogen‐containg substrates or hypervalent iodine reagents, usually stoichiometric amount, are inevitably adopted for the transformations. In the continuation of our recent interest in base promoted cyclization reaction for the synthesis of structurally interesting heterocyclic compounds,,, we herein report an efficient and environmentally friendly approach to indolizines via cesium carbonate mediated cycloisomerization of homopropargyl pyridines. To the best of our knowledge, this represents the first example of transition metal and halogen free transformations of the kind ,…”