28864-65-5Relevant academic research and scientific papers
Phthalide synthesis through dehydrogenated lactonization of the C(sp3)-H bond by photoredox catalysis
Cai, Shunyou,Cai, Zhixiong,Chen, Shanyi,Huang, Mingqiang,Lai, Qihong,Lin, Yulin,Liu, Chao,Liu, Hui
, p. 8212 - 8216 (2021/10/29)
A practical and efficient method is established for the direct oxidative lactonization of the C(sp3)-H bonds relying on visible-light-induced photoredox catalysis. This protocol expediently allows the delivery of diverse phthalides using oxygen as the sole terminal oxidant under metal-free conditions at room temperature. Notably, the choice of an appropriate hydrogen atom transfer (HAT) cocatalyst is revealed to be critical for the success of this process.
The reaction of arylcoppermagnesium and other organometallic reagents with phthalic anhydride
Rahman, Mohammed T.,Nahar, Syeda K.
, p. 201 - 208 (2007/10/02)
Arylcoppermagnesium reagents, prepared from 5ArMgX + 2.5CuI, (Ar = 4-CH3C6H4, 4-CH3OC6H4, 4-ClC6H4, 2-C4H3S) react with one equivalent of phthalic anhydride in ether or THF at -5 deg C for 2.5 h to give 2-aroylbenzoic acid in 83-98percent yields.The phenylcoppermagnesium reagent (Ar = C6H5) under similar conditions gives 2-benzoylbenzoic acid and 3,3-diphenylphthalide in 40-42percent and 42-45percent yield, respectively.The yield of the 2-benzoylbenzoic acid rises to 93percent in the presence of dimethyl sulphide.Under these conditions no phthalide is formed.Lithium diphenylcuprate reactswith phthalic anhydride in ether-hexane to give 92percent of 2-benzoylbenzoic acid and 7percent of 3,3-diphenylphthalide.The reaction of phenylcopper reagent, prepared from PhMgBr + CuI, under similar conditions is slow and gives 2-benzoylbenzoic acid in 15percent yield.The reaction of phenylmagnesium bromide in the presence or absence of catalytic amounts of copper(I) iodide gives unsatisfactory results.Use of two equivalents of phenyllithium with one equivalent of phthalic anhydride, on the other hand, affords 3,3-diphenylphthalide in 77percent yield.The mechanisms of these reactions are discussed.
