Copper- or Nickel-Enabled Oxidative Cross-Coupling of Unreactive C(sp3)–H Bonds with Azole C(sp2)–H Bonds: Rapid Access to β-Azolyl Propanoic Acid Derivatives
摘要:
beta-Azolyl propanoic acid derivatives are frequently found in biologically active molecules and pharmaceuticals. Here, we report the oxidative heteroarylation of unactivated C(sp(3))-H bonds with azole C(sp(2))-H bonds via copper or nickel catalysis with the aid of removable bidentate auxiliary, which provides a rapid pathway to beta-azolyl propanoic acid derivatives. A variety of azoles such as oxazole, benzoxazole, thiazole, benzothiazoles, benzimidazole, purine, and even [1,2,4]triazolo[1,5-a]pyrimidine could be engaged
Rhodium(<scp>iii</scp>)-catalyzed C–H activation/[4+3] annulation of N-phenoxyacetamides and α,β-unsaturated aldehydes: an efficient route to 1,2-oxazepines at room temperature
We report herein a Rh(III)-catalyzed cyclization of N-nitrosoanilines with alkynes for streamlined synthesis of indoles. The synthetic protocol features a distinct internal oxidant, N-N bond, as a reactive handle for catalyst turnover, as well as a hitherto tantalizingly elusive intermolecular redox-neutral manifold, predicated upon C-H activation, for the formation of a five-membered azaheterocycle
Strained Dehydrogenative Ring Closure of Phenylcarbazoles
作者:Alexander W. Jones、Marie-Laure Louillat-Habermeyer、Frederic W. Patureau
DOI:10.1002/adsc.201401136
日期:2015.3.23
and strained dehydrogenativeringclosure, for example, in phenylcarbazoles? Since the works of Buchwald and Fagnou, palladium‐catalysed ring‐closing dehydrogenative reactions are legion, but will not operate when the strain at the reductive elimination stage becomes too large. We propose here a “muscled up” super‐oxidative palldium‐catalysed CH activation method for the ringclosure of strained phenylcarbazoles
作者:N. D. Kagramanov、I. O. Bragilevskii、V. A. Yablokov、A. V. Tomadze、S. V. Krasnodubskaya、A. K. Mal'tsev
DOI:10.1007/bf00954802
日期:1986.7
Access to multi-functionalized oxazolines via silver-catalyzed heteroannulation of enamides with sulfoxonium ylides
作者:Rui-Hua Liu、Qi-Chao Shan、Ya Gao、Teck-Peng Loh、Xu-Hong Hu
DOI:10.1016/j.cclet.2020.10.007
日期:2021.4
efficient Ag-catalyzed [4 + 1] heteroannulation reaction of enamides with α-carbonyl sulfoxonium ylides. The diastereoselective transformation provides a practical access to a diverse range of multi-functionalized oxazoline derivatives. The synthetic utility of the resultant tetra-substituted oxazolines is further demonstrated by a series of useful manipulations into valuable building blocks of pharmaceutical