I 2 -catalyzed one-pot synthesis of benzofuro/thieno[2,3- b ]pyrrole motifs

Abstract

A novel I 2 -catalyzed one-pot multicomponent protocol for the synthesis of a variety of elusive furo[2,3-b] pyrrole and thieno[2,3-b]pyrrole libraries has been established. To date, cyclization among alkanone, hydrazine and 2-bromobenzofuran or 2-bromobenzo[b]thiophene has not been explored in one-pot. Thus, the proposed single step protocol provides a versatile alternative to existing routes for accessing useful furo[2,3-b]pyrrole and thieno[2,3-b]pyrrole libraries.

A Review on Molecular Iodine Catalyzed/Mediated Multicomponent Reactions

“…Chacko and Shivashankar [36] have reported a single method for formation of both furo[2,3‐ b ]pyrroles 25 and thieno[2,3‐ b ]pyrroles 26 by iodine catalyzed multicomponent tandem cyclization reaction of 2‐bromobenzofuran/2‐bromobenzo[ b ]thiophene, ketones and hydrazine (Scheme 11). Substrate scope of reaction was extended to various cyclic and acyclic aliphatic ketones with good to excellent yield of desired product, however, scope of variously substituted 2‐bromobenzofurans was limited to 5‐nitro derivative only which gave comparable results.…”

The role of halogen bonds in the catalytic mechanism of the iso-Nazarov cyclization reaction: a DFT study

“…In addition, molecular iodine can also efficiently promote the carbonyl–olefin metathesis reaction 19 under mild reaction conditions and the synthesis of heterocycles of quinolones, 20 pyrroles, etc. 21,22…”

“…In addition, molecular iodine can also efficiently promote the carbonyl-olefin metathesis reaction 19 under mild reaction conditions and the synthesis of heterocycles of quinolones, 20 pyrroles, etc. 21,22 Nazarov cyclization reaction 23,24 is one of the most important organic reactions for the synthesis of five-membered carbon rings and the construction of the C-C bond in the cyclization reaction. It can occur through simple orbital recombination and usually occurs via the 4p electrocyclization of the pentadienyl cation.…”

Montmorillonite K-10 catalyzed Mannich reaction: Synthesis of aminonaphthoquinone derivatives from Lawsone

“…In connection with our consistent interest in the development of efficient synthetic methodologies, [48][49][50][51][52][53][54][55][56][57][58][59] we report herein a new and efficient protocol using clay catalytic system to access the synthesis of relevant scaffolds and some novel aminonaphthoquinone derivatives with benzothiazole moiety from readily available substrates.…”