Site-selective C–H bond carbonylation with CO<sub>2</sub> and cobalt-catalysis
作者:Nagaraju Barsu、Deepti Kalsi、Basker Sundararaju
DOI:10.1039/c8cy02060d
日期:——
in situ-produced CO gas for C–Hbondcarbonylation using earth-abundant cobalt catalysts. The ease of handling CO2 gas at atmospheric pressure allows us to prepare 13C labelled compounds which are otherwise difficult to achieve. The procedure developed makes it possible to utilize CO2 as a CO source, which can be widely applied as a C1 synthon that can be incorporated between C–H and N–H bonds of aromatic
Copper-promoted site-selective carbonylation of sp<sup>3</sup> and sp<sup>2</sup> C–H bonds with nitromethane
作者:Xuesong Wu、Jinmin Miao、Yanrong Li、Guigen Li、Haibo Ge
DOI:10.1039/c6sc01087c
日期:——
Copper-promoted direct carbonylation of unactivated sp3 C–H and aromatic sp2 C–H bonds of amides was developed using nitromethane as a novel carbonyl source. The sp3 C–H functionalization showed high site-selectivity by favoring the C–H bonds of α-methyl groups. The sp2 C–Hcarbonylation featured high regioselectivity and good functional group compatibility. Kinetic isotope effect studies indicated
Catalytically Relevant Intermediates in the Ni-Catalyzed C(sp<sup>2</sup>)–H and C(sp<sup>3</sup>)–H Functionalization of Aminoquinoline Substrates
作者:Pronay Roy、James R. Bour、Jeff W. Kampf、Melanie S. Sanford
DOI:10.1021/jacs.9b09109
日期:2019.10.30
at -30 °C to afford isolable five-coordinate NiIII species. The NiIII σ-aryl complexes proved inert toward C(sp2)-I bond-forming reductive elimination under all conditions examined (up to 140 °C in DMF). In contrast, a NiIII σ-alkyl analogue underwent C(sp3)-N bond-forming reductive elimination at 140 °C in DMF to afford a β-lactam product. However, despite the ability of this latter NiIII species
Proton Grease: An Acid Accelerated Molecular Rotor
作者:Brent E. Dial、Perry J. Pellechia、Mark D. Smith、Ken D. Shimizu
DOI:10.1021/ja2120184
日期:2012.2.29
A molecularrotor was designed that rotates 7 orders of magnitude faster upon protonation. The quinoline rotor is based on a rigid N-arylimide framework that displays restricted rotation due to steric interaction between the quinoline nitrogen and imide carbonyls. At rt (23 °C), the rotor rotates slowly (t(1/2) = 26 min, ΔG(‡) = 22.2 kcal/mol). However, upon addition of 3.5 equiv of acid the rotor rotates
Cobalt-catalysed C–H carbonylative cyclisation of aliphatic amides
作者:Patrick Williamson、Alicia Galván、Matthew J. Gaunt
DOI:10.1039/c6sc05581h
日期:——
A cobalt-catalysed C–H carbonylation of aliphatic carboxamide derivatives is described, employing commercially available Co(II)-salts in the presence of a silver oxidant. This operationally simple process utilises an atmospheric pressure of CO and generates a range of substituted succinimide products bearing diverse functional groups that can be successfully accessed via this methodology.