A new class of N-doped ionic PAHs<i>via</i>intramolecular [4+2]-cycloaddition between arylpyridines and alkynes
作者:Ravindra D. Mule、Aslam C. Shaikh、Amol B. Gade、Nitin T. Patil
DOI:10.1039/c8cc05743e
日期:——
Reported herein, for the first time, is a copper-promoted intramolecular [4+2]-cycloaddition cascade to access ionic N-doped polycyclic aromatic hydrocarbons (PAHs) with tunable emission wavelengths. It is shown that the reaction can be made catalytic with respect to Cu(OTf)2 when an external oxidant, Selectfluor, was used.
Oxidative Intramolecular 1,2‐Amino‐Oxygenation of Alkynes under Au
<sup>I</sup>
/Au
<sup>III</sup>
Catalysis: Discovery of a Pyridinium‐Oxazole Dyad as an Ionic Fluorophore
作者:Aslam C. Shaikh、Dnyanesh S. Ranade、Pattuparambil R. Rajamohanan、Prasad P. Kulkarni、Nitin T. Patil
DOI:10.1002/anie.201609335
日期:2017.1.16
Oxidative intramolecular 1,2‐amino‐oxygenation reactions, combining gold(I)/gold(III) catalysis, is reported. The reaction provides efficient access to a structurally unique ionic pyridinium‐oxazole dyad with tunable emission wavelengths. The application of these fluorophores as potential biomarkers has been investigated.
Gold-Catalyzed Cycloisomerization of Pyridine-Bridged 1,8-Diynes: An Expedient Access to Luminescent Cycl[3.2.2]azines
作者:Chetan C. Chintawar、Manoj V. Mane、Akash G. Tathe、Suprakash Biswas、Nitin T. Patil
DOI:10.1021/acs.orglett.9b02677
日期:2019.9.6
Gold-catalyzed diyne cycloisomerizations involving carbene/alkyne metathesis have been the focal point of attention for the past few years as it offers great potential to build complex polycyclic architectures. However, the design of novel cycloisomerizations has been mostly limited to 1,5/1,6- diynes and has remained very challenging to apply for higher 1,n-diynes. Herein, we disclose an unprecedented
Controlling the Selectivity Patterns of Au-Catalyzed Cyclization–Migration Reactions
作者:Mo Chen、Naijing Su、Tianning Deng、Donald J. Wink、Yingwei Zhao、Tom G. Driver
DOI:10.1021/acs.orglett.8b03888
日期:2019.3.15
2-dihydronaphthalenes. Our data suggests that this transformation occurs via a gold-stabilized cyclopropyl carbinyl cation, which triggers either a [1,2] carboxylate shift or a less favorable [1,2] aryl shift. The relative rates of these migrations can be controlled by the identity of the ligand or by stabilizing the mesomeric cation.
Enantioselective Folding of Enynes by Gold(I) Catalysts with a Remote <i>C</i><sub>2</sub>-Chiral Element
作者:Giuseppe Zuccarello、Joan G. Mayans、Imma Escofet、Dagmar Scharnagel、Mariia S. Kirillova、Alba H. Pérez-Jimeno、Pilar Calleja、Jordan R. Boothe、Antonio M. Echavarren
DOI:10.1021/jacs.9b06326
日期:2019.7.31
Chiral gold(I) catalysts have been designed based on a modified JohnPhos ligand with a distal C2-2,5-diarylpyrrolidine that creates a tight binding cavity. The C2-chiral element is close to where the C-C bond formation takes place in cyclizations of 1,6-enynes. These chiral mononuclear catalysts have been applied for the enantioselective 5-exo-dig and 6-endo-dig cyclization of different 1,6-enynes