4030-17-5Relevant articles and documents
Halogen-Bridged Methylnaphthyl Palladium Dimers as Versatile Catalyst Precursors in Coupling Reactions
Doppiu, Angelino,Goo?en, Lukas J.,Hu, Zhiyong,Pirkl, Nico,Sivendran, Nardana
supporting information, p. 25151 - 25160 (2021/10/19)
Halogen-bridged methylnaphthyl (MeNAP) palladium dimers are presented as multipurpose Pd-precursors, ideally suited for catalytic method development and preparative organic synthesis. By simply mixing with phosphine or carbene ligands, they are in situ converted into well-defined monoligated complexes. Their catalytic performance was benchmarked against state-of-the-art systems in challenging Buchwald–Hartwig, Heck, Suzuki and Negishi couplings, and ketone arylations. Their use enabled record-setting activities, beyond those achievable by optimization of the ligand alone. The MeNAP catalysts permit syntheses of tetra-ortho-substituted arenes and bulky anilines in near-quantitative yields at room temperature, allow mono-arylations of small ketones, and enable so far elusive cross-couplings of secondary alkyl boronic acids with aryl chlorides.
Imidazotetrazines as Weighable Diazomethane Surrogates for Esterifications and Cyclopropanations
Svec, Riley L.,Hergenrother, Paul J.
supporting information, p. 1857 - 1862 (2019/12/27)
Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to perform the unique chemistry of diazomethane, these suffer from diminished reactivity and/or correspondingly harsher conditions. Herein, we describe the repurposing of imidazotetrazines (such as temozolomide, TMZ, the standard of care for glioblastoma) for use as synthetic precursors of alkyl diazonium reagents. TMZ was employed to conduct esterifications and metal-catalyzed cyclopropanations, and results show that methyl ester formation from a wide variety of substrates is especially efficient and operationally simple. TMZ is a commercially available solid that is non-explosive and non-toxic, and should find broad utility as a replacement for diazomethane.
Lewis Base-Promoted Ring-Opening 1,3-Dioxygenation of Unactivated Cyclopropanes Using a Hypervalent Iodine Reagent
Gieuw, Matthew H.,Ke, Zhihai,Yeung, Ying-Yeung
supporting information, p. 3782 - 3786 (2018/03/13)
A facile and effective system has been developed for the regio- and chemoselective ring-opening/electrophilic functionalization of cyclopropanes through C?C bond activation by [bis(trifluoroacetoxy)iodo]benzene with the aid of the Lewis basic promoter p-toluenesulfonamide. The p-toluenesulfonamide-promoted system works well for a wide range of cyclopropanes, resulting in the formation of 1,3-diol products in good yields and regioselectivity.
