- Phthalide synthesis through dehydrogenated lactonization of the C(sp3)-H bond by photoredox catalysis
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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.
- Cai, Shunyou,Cai, Zhixiong,Chen, Shanyi,Huang, Mingqiang,Lai, Qihong,Lin, Yulin,Liu, Chao,Liu, Hui
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p. 8212 - 8216
(2021/10/29)
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- C-F bond cleavage by intramolecular SN2 reaction of alkyl fluorides with O- and N-nucleophiles
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The nueleophilic substitution of alkyl fluorides was achieved in the intramolecular reactions with O- and N-nucleophiles. The intramolecular defluorinative cyclization reaction was influenced by the nature of nucleophiles, the size of the ring to be forme
- Zhang, Laijun,Zhang, Wei,Liu, Jun,Hu, Jinbo
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supporting information; experimental part
p. 2850 - 2853
(2009/08/08)
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- Electron-transfer-induced reductive cleavage of phthalans: Reactivity and synthetic applications
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The behavior of phthalan (1a) was investigated under conditions of electron transfer from alkali metals in aprotic solvents. Reaction with lithium in the presence of a catalytic amount of naphthalene in THF led to the reductive cleavage of an arylmethyl carbon-oxygen bond, with formation of a stable dilithium compound. Trapping of this intermediate with several electrophiles (alkyl halides, carbonyl derivatives, CO2) was successful. The extension of this procedure to several substituted phthalans (1b-i) was investigated, and the regiochemistry as well as the synthetic usefulness of these reactions are discussed.
- Azzena, Ugo,Demartis, Salvatore,Melloni, Giovanni
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p. 4913 - 4919
(2007/10/03)
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- Direct Conversion of Alcohols into Thiols
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A simple one-pot reaction between alcohols and 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide (Lawesson's reagent, LR) affords the corresponding thiols, accompanied by dehydration products, alkenes.Treatment of acyclic 1,4-diols with LR gives the 1,3-dienes. o-(Dihydroxymethyl)benzene derivatives yield the 1,3-dihydrobenzothiophenes when treated with LR.
- Nishio, Takehiko
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p. 1113 - 1118
(2007/10/02)
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- Direct ortho-Metalation of Benzyl Alcohols. A Novel Method of Preparing ortho-Substituted Benzyl Alcohols
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Benzyl alcohol and other phenylcarbinols (8a - 11a), including α-tetralol (12a), are doubly deprotonated by excess n-butyllithium/TMEDA in pentane to give lithium ortho-lithioalkoxides (2, 8b - 12b).Alkylations (-> 3a - d, table 1), reactions with heteroelectrophiles (-> 3e - k, table 2) and with carbonyl compounds (-> 6, 13 - 17, tables 3 and 4), as well as subsequent reactions of the primary adducts (-> phthalanes 7, table 3) furnish a large variety of ortho-substituted benzyl alcohol derivatives.The scope and limitations of the dilithioorganyls (sections B and C), their mode of formation (section A), and attempts to doubly metalate 2-phenylethanol are discussed.
- Meyer, Norbert,Seebach, Dieter
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p. 1304 - 1319
(2007/10/02)
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