A protocol on chemoselective cobalt(II) porphyrin-catalyzed intramolecular cyclopropanation of N-alkyl indoles/pyrroles with alkylcarbenes has been developed. The reaction enables the rapid construction of a range of nitrogen-containing polycyclic compounds in moderate to high yields from readily accessible materials. These N-containing polycyclic compounds can be converted into a variety of N-heterocycles with potential synthetic and biological interest. Compared to their N-tosylhydrazone counterparts, the use of bulky N-2,4,6-triisopropylbenzenesulfonyl hydrazones as carbene precursors allows cyclopropanation to occur under milder reaction conditions.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/anie.201506418 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Molecular Evidence for the Catalytic Process of Cobalt Porphyrin Catalyzed Oxygen Evolution Reaction in Alkaline Solution.
J Am Chem Soc
May 2019
CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing National Laboratory for Molecular Science (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , China.
We report an electrochemical scanning tunneling microscopy (ECSTM) study of the 5,10,15,20-tetraphenyl-21 H,23 H-porphyrin cobalt(II) (CoTPP) catalyzed oxygen evolution reaction (OER). A highly ordered self-assembled monolayer of CoTPP is formed on the Au(111) electrode. Cyclic voltammetry results show the OER activity of the electrode is enhanced with the increasing alkalinity of the electrolytes.
View Article and Find Full Text PDFPorphyrin Cobalt(III) "Nitrene Radical" Reactivity; Hydrogen Atom Transfer from Ortho-YH Substituents to the Nitrene Moiety of Cobalt-Bound Aryl Nitrene Intermediates (Y = O, NH).
Molecules
February 2016
Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
In the field of cobalt(II) porphyrin-catalyzed metallo-radical reactions, organic azides have emerged as successful nitrene transfer reagents. In the pursuit of employing ortho-YH substituted (Y = O, NH) aryl azides in Co(II) porphyrin-catalyzed nitrene transfer reactions, unexpected hydrogen atom transfer (HAT) from the OH or NH₂ group in the ortho-position to the nitrene moiety of the key radical-intermediate was observed. This leads to formation of reactive ortho-iminoquinonoid (Y = O) and phenylene diimine (Y = NH) species.
View Article and Find Full Text PDFCobalt(II) Porphyrin-Catalyzed Intramolecular Cyclopropanation of N-Alkyl Indoles/Pyrroles with Alkylcarbene: Efficient Synthesis of Polycyclic N-Heterocycles.
Angew Chem Int Ed Engl
January 2016
HKU Shenzhen Institute of Research & Innovation, Shenzhen, China.
A protocol on chemoselective cobalt(II) porphyrin-catalyzed intramolecular cyclopropanation of N-alkyl indoles/pyrroles with alkylcarbenes has been developed. The reaction enables the rapid construction of a range of nitrogen-containing polycyclic compounds in moderate to high yields from readily accessible materials. These N-containing polycyclic compounds can be converted into a variety of N-heterocycles with potential synthetic and biological interest.
View Article and Find Full Text PDFMechanism of cobalt(II) porphyrin-catalyzed C-H amination with organic azides: radical nature and H-atom abstraction ability of the key cobalt(III)-nitrene intermediates.
J Am Chem Soc
August 2011
Van 't Hoff Institute for Molecular Sciences (HIMS), Homogeneous and Supramolecular Catalysis, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
The mechanism of cobalt(II) porphyrin-catalyzed benzylic C-H bond amination of ethylbenzene, toluene, and 1,2,3,4-tetrahydronaphthalene (tetralin) using a series of different organic azides [N(3)C(O)OMe, N(3)SO(2)Ph, N(3)C(O)Ph, and N(3)P(O)(OMe)(2)] as nitrene sources was studied by means of density functional theory (DFT) calculations and electron paramagnetic resonance (EPR) spectroscopy. The DFT computational study revealed a stepwise radical process involving coordination of the azide to the metal center followed by elimination of dinitrogen to produce unusual "nitrene radical" intermediates (por)Co(III)-N(•)Y (4) [Y = -C(O)OMe, -SO(2)Ph, -C(O)Ph, -P(O)(OMe)(2)]. Formation of these nitrene radical ligand complexes is exothermic, predicting that the nitrene radical ligand complexes should be detectable species in the absence of other reacting substrates.
View Article and Find Full Text PDFThe radical mechanism of cobalt(II) porphyrin-catalyzed olefin aziridination and the importance of cooperative H-bonding.
Dalton Trans
June 2011
Homogeneous and Supramolecular Catalysis group, Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam.
The mechanism of cobalt(II) porphyrin-mediated aziridination of styrene with PhSO(2)N(3) was studied by means of DFT calculations. The computations clearly indicate the involvement of a cobalt 'nitrene radical' intermediate in the Co(II)(por)-catalyzed alkene aziridination. The addition of styrene to this species proceeds in a stepwise fashion via radical addition of the 'nitrene radical'C to the C=C double bond of styrene to form a γ-alkyl radical intermediate D.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!