One-pot synthesis of aryl fluorides by [3+3] cyclization of 1,3-bis(silyl enol ethers) with 2-fluoro-3-silyloxy-2-en-1-ones

Synthesis of Fluorinated Arenes and Hetarenes Based on One-Pot Cyclizations of 1,3-Bis(trimethylsilyloxy)-1,3-butadienes

“…18 Based on our previously reported cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 3-silyloxy-2-en-1-ones, 9 we developed a new synthetic approach to 4-fluorophenols by formal [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 2-fluoro-3-silyloxy-2-en-1-ones. 19 2-Fluoro-1,3-diones are available by reaction of 1,3-diketones with fluorine, 20 N-fluorobis(trifluoromethyl)sulfonimide 21 or Selectfluor. 22 In our hands, the use of Selectfluor proved to be very convenient.…”

Modular Construction of Fluoroarenes from a New Difluorinated Building Block by Cross‐Coupling/Electrocyclisation/Dehydrofluorination Reactions

“…For simple arenes, these novel methods are hard to beat; however, not all precursor types are readily available. A strategically different approach to fluoroarene synthesis could start from nonfluorinated species like indanones by carbene transfer and rearrangement, or from readily available fluorinated building blocks like fluoroenynes, fluorinated dienophiles or most recently, and very effectively, from difluoroalkenes by electrophilic cyclisation or Ni‐catalysed [2+2+2]‐cycloaddition. Acetal 1 and carbamate 2 (Figure ), which are readily‐prepared from trifluoroethanol, can be converted to organozinc halides 3 and 4 , which can be deployed in Negishi coupling reactions with aryl halides.…”

Pseudosymmetry, polymorphism and weak interactions: 4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carboxylic acid and its derivatives

“…In the Cambridge Structural Database 10 (ver. 5.34, last update May 2013) there are no structures of 1,1′:3′,1′′-terphenyl derivatives with both hydroxyl and carboxyl functions (in disposition like that in 1), and there is only one ester (methyl 2′-fluoro-5′-hydroxy-1,1′;3′,1′′-terphenyl-4′-carboxy-late 11 ) and one carboxamide (N-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)-4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carboxamide 12 ). The database analysis prompted to another interesting fact: for compounds with a benzene ring with hydroxyl and carboxylic acid functions in the neighbouring positions (only organic, no fused rings) we have found over the average number of the structures with multiple molecules (Z′ > 1).…”