Studies towards iodine-catalyzed dehydrative-cycloisomerization of pent-4-yne-1,2-diols to di- and tri-substituted furans

Studies in the rearrangement reactions involving camphorquinone

“…Surprisingly however, it did not nd many applications in organic synthesis. 20 Previously, we have established a method for the synthesis of 2methylfuran appended polycyclic aromatic hydrocarbons Fig. 1 Structures of (+)-camphor 1 and (À)-camphorquinone 2, furan appended camphor motif 3 intended for preparation and perhydrobenzofuran 4 actually formed.…”

“…Surprisingly however, it did not find many applications in organic synthesis. 20 Previously, we have established a method for the synthesis of 2-methylfuran appended polycyclic aromatic hydrocarbons (PAHs) from corresponding 1,2-diketones. 21 Barbier type allylation on one of the two carbonyl groups, reduction of the remaining carbonyl, iodine mediated 5- exo -dig cyclization yielded 5-methylfuran appended to PAHs.…”

Synthesis of 2-Aryl Acetophenones via Hydrobromination and Oxy-isomerization of (o-Arylethynyl)benzyl Alcohols

“…2-Aryl acetophenones are useful building blocks to access many heterocycles, including furans, − benzofurans, − pyrroles, − indoles, − imidazoles, − pyridines, − pyrimidines, − quinolines, − quinoxalines, − and isoxazoles, etc. − Various methods have been developed to prepare 2-aryl acetophenones; however, hydration of diaryl acetylenes is a direct and atom-economical pathway to access this family of compounds, and new development in this direction continues to receive the attention of chemists. , In addition to mercury­(II), the classical catalyst used to activate alkynes for hydration, − various metal salts or complexes have been applied for this purpose, including iron, − copper, , ruthenium, − rhodium, , gold, − platinum, , and other metals, ,,…”

Oxidative C–H Acyloxylation of Acetone with Carboxylic Acids under Iodine Catalysis

“…Iodine donor mediated cyclization of 2-alkynyl-1-methylene azide aromatics, 3 enynes, 4 enamines, 5 anilines with methyl ketones, 6 aryl methyl ketoxime acetates with triethylamine, 7 and aryl methylketones with 4-hydroxycoumarins, 8 and C-C/C-O bond-formation of 1,3-dienes with malonate esters 9 have been developed for the synthesis of valuable cyclic products. Furthermore, many cyclization reactions have also been conducted under iodine catalysis to give good results; these include domino Michael additionintramolecular cyclization, 10 dehydrative-cycloisomerization of pent-4-yne-1,2-diols, 11 C-N and C-C bonds formation, 12 Nazarov or iso-Nazarov cyclization, 13 hydroamination 14 or deamination 15 of styrene, ring opening of 1-aryltetrahydro--carbolines, 16 and intramolecular carbonylolefin metathesis. 17 In multicomponent cascade systems, iodine-catalyzed cyclization for the synthesis of benzothiazoles, 18 pyrazolones, 19 2-phenylnaphtho[2,1-d]selenazoles 20 were also reported.…”