Reaction of arynes with trifluoroacetylated β‐diketones: Novel formation of isocoumarins and phenanthrenes. Issue 5 (2nd November 2018)

• Record Type: Journal Article
• Authors: Okuma, Kentaro; Tanabe, Yukiko; Fukami, Takuto; Ishibashi, Yuto
• Is Part Of: Heteroatom chemistry. Volume 29:Issue 5/6(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-11-02
• Subjects: Heterocyclic chemistry -- Periodicals; 547.59
• DOI: 10.1002/hc.21444
• Languages: English
• ISSNs: 1042-7163

Abstract

Abstract: Polysubstituted isocoumarins were synthesized by the reaction of substituted 2‐(trimethylsilyl)aryl triflates with trifluoromethylated β‐diketones in the presence of CsF. The reaction proceeded through carbon‐carbon bond insertion of aryne and intramolecular cyclization to form intermediates of alcohol anions, which extruded trifluoromethyl anion to afford isocoumarins. By using CuBr as a catalyst, 2 eq. of aryne reacted with β‐diketones to afford phenanthrenes and 1, 2‐diarylethanones. Although reaction of 2‐(trimethylsilyl)phenyl triflate with 1, 1, 1‐trifluoro‐4′‐methylbenzoylacetone in the presence of CsF gave 3‐(4′‐methylphenyl)isocoumarin in 67% yield, addition of 0.2 eq. of CuCN resulted in the formation of 9‐(4‐methylbenzoyl)‐10‐trifluoromethylphenanthrene in 35% yield.