Arylation of ketones with preservation of the chirality in configurationally unstable α‐chiral ketones has been achieved by the palladium‐catalyzed cross‐coupling reaction between tosylhydrazones and aryl halides (see scheme; Boc=tert‐butoxycarbonyl, Ts=4‐toluenesulfonyl). The regioselectivity in the β‐hydride elimination step is key for the retention of configuration.
Ring-fused and spiro cyclopentenones by Ni(CO)4-promoted intermolecular carbonylative cycloaddition of acetylenes with 3-halo- and 1-(halomethyl)cycloalkenes
作者:Lluis Pages、Amadeu Llebaria、Francisco Camps、Elies Molins、Carles Miravitlles、Josep M. Moreto
DOI:10.1021/ja00052a047
日期:1992.12
The title carbonylativecycloaddition of five- to eight-member ring 3-halo- and 1-(halomethyl)cycloalkenes with different acetylenes was studied. From moderate to good yields of ring-fused and spiro cyclopentenone derivatives were obtained, especially in the reaction with acctylenes bearing electron-withdrawing substituents by propa selection of the reaction conditions to avoid the acetylene polyinsertion
Preparation of α-Oxygenated Ketones by the Dioxygenation of Alkenyl Boronic Acids
作者:Aditi S. Patil、Dong-Liang Mo、Heng-Yen Wang、Daniel S. Mueller、Laura L. Anderson
DOI:10.1002/anie.201202704
日期:2012.7.27
Two in two: Dioxygenation of alkenylboronicacids has been achieved with N‐hydroxyphthalimide. The two‐step process involves etherification of an alkenylboronicacid with N‐hydroxyphthalimide followed by a [3,3] rearrangement. The dioxygenated product can then be hydrolyzed to form either the corresponding α‐hydroxy ketone or the α‐benzoyloxy ketone.
Umpolung-like Cross-coupling of Tosylhydrazones with 4-Hydroxy-2-pyridones under Palladium Catalysis
作者:Tania Katsina、Kyriaki Eleni Papoulidou、Alexandros L. Zografos
DOI:10.1021/acs.orglett.9b03119
日期:2019.10.4
Tosylhydrazones under palladium catalysis were found to perform cross-couplingreactions with 4-hydroxy-2-pyridones. The umpolung-like reactivity, between the α-carbon of tosylhydrazone and the 3-position of the heterocycle, which is observed in the obtained products, indicates the directed sp3-CH-activation of an alkylated phenol intermediate by the pendant 3-palladated heterocycle. The reaction and its intercepted
Abstract In an environmentally benign solvent-free system, oximes and hydrazones are rapidly transformed into parent carbonylcompounds using peroxymonosulfate on silica gel under microwave irradiation in good to excellent yields.