Insights into highly selective ring expansion of oxaziridines under Lewis base catalysis: a DFT study

2019 ◽  
Vol 6 (5) ◽  
pp. 679-687 ◽  
Author(s):  
Qiao-Chu Zhang ◽  
Xue Li ◽  
Xinghua Wang ◽  
Shi-Jun Li ◽  
Ling-Bo Qu ◽  
...  
Keyword(s):  
Ring Expansion ◽  
Lewis Base ◽  
Base Catalysis ◽  
Dft Study ◽  
Ring Expansion Reaction ◽  
First Time

The possible mechanism and stereoselectivity of the NHC-catalyzed ring expansion reaction of oxaziridines have been theoretically studied for the first time.

Synthesis of α-Thiooximes by Addition of Thiols to N,N-Bis(oxy)-enamines: A Comparative Study of S-, N-, and O-Nucleo­philes in Michael Reaction with Nitrosoalkene Species

Synlett ◽  
2018 ◽  
Vol 29 (10) ◽  
pp. 1334-1339 ◽  
Author(s):  
Alexey Sukhorukov ◽  
Yana Naumovich ◽  
Aleksandr Kokuev ◽  
Sema Ioffe
Keyword(s):  
Comparative Study ◽  
Nucleophilic Addition ◽  
Michael Reaction ◽  
Lewis Base ◽  
Base Catalysis ◽  
Relative Reactivity ◽  
Efficient Manner ◽  
Highly Efficient ◽  
Relative Nucleophilicity ◽  
First Time

Nucleophilic addition of thiols to N,N-bis(oxy)enamines (nitrosoalkene acetals) produce valuable α-thiooximes in a highly efficient manner. The reaction was found to be solvent-dependent, likely because of distinct mechanisms operating in nonpolar and basic solvents (involving either Brønsted acid or Lewis base catalysis). By performing a series of competition experiments, the relative reactivity of S-, N-, and O-nucleophiles in reaction with N,N-bis(oxy)enamines was determined for the first time. Interestingly, the relative nucleophilicity was found to be highly dependent on the solvent, which allows regioselective control of these reactions by using an appropriate medium.

Nature of Lewis Base Catalysis of 1,3-Dipolar Cycloaddition of Methyl Diazoacetate to Methyl Acrylate; NMR Kinetic Spectroscopy and DFT Study

2017 ◽  
Vol 121 (27) ◽  
pp. 6601-6609
Author(s):  
Mikhail Yu. Ovchinnikov ◽  
Tagir A. Yangirov ◽  
Alexander N. Lobov ◽  
Rimma M. Sultanova ◽  
Sergey L. Khursan
Keyword(s):  
Methyl Acrylate ◽  
Lewis Base ◽  
Base Catalysis ◽  
Dft Study ◽  
Dipolar Cycloaddition ◽  
Kinetic Spectroscopy ◽  
Methyl Diazoacetate

Unusual Ring-Expansion Reaction of Polyfluorinated Norbornenoxetanes

Synthesis ◽  
2007 ◽  
Vol 2007 (9) ◽  
pp. 1349-1354 ◽  
Author(s):  
Viacheslav Petrov ◽  
Will Marshall
Keyword(s):  
Ring Expansion ◽  
Ring Expansion Reaction

Synthesis and Ring Cyclization - Expansion - Contraction Reactions of Some New 2,2-Disubstituted Indan-1,3-diones and Related Compounds

2006 ◽  
Vol 59 (1) ◽  
pp. 59 ◽  
Author(s):  
Craig J. Roxburgh ◽  
Lee Banting
Keyword(s):  
Catalytic Hydrogenation ◽  
Pyridine Ring ◽  
Functional Group ◽  
Chemical Properties ◽  
Ring Expansion ◽  
Ring Structure ◽  
Side Reactions ◽  
The Third ◽  
Ring Expansion Reaction ◽  
Related Compounds

We have found that the hydrochloride of 2-phenyl-2-[2-(2-piperidyl)ethyl]-4,5,6,7-tetrahydroindan-1,3-dione 1 possesses marked analgesic activity (100% inhibition referenced to codeine) and report, as part of an extensive synthetic program, the synthesis of 38 new and structurally related compounds. Selective catalytic hydrogenation of the pyridine ring of 2-phenyl-2-[2-(2-pyridyl)ethyl]-indan-1,3-dione 2 yields the nine-membered nitrogen-containing heterocycle 6 by a novel ring cyclization–expansion reaction. The structural and functional group parameters required for this novel ring-expansion reaction have been extensively and thoroughly investigated through the synthesis of a series of structurally related compounds; principally by modification, substitution, and replacement of the various functionality contained within 2. In addition, we report the synthesis of a series of new 2-methyl-2-(ω-N-phthalimidoalkyl)-indan-1,3-diones 41, 45, and 53, two of which, like the parent 2-phenyl substituted indan-1,3-dione 2, also undergo a novel ring cyclization–expansion reaction to yield eight- and nine-membered nitrogen-containing rings. However, in these cases, further transannular reactions occur to produce the new 5,5- and 5,6-ring-fused nitrogen-containing heterocycles 44, 48 and 51, 52. Hydrazinolysis of the third, 2-methyl-2-(4-N-phthalimidobutyl)-indan-1,3-dione yields the new azepine-containing ring structure 56 by direct cyclization. Furthermore, some interesting and unexpected chemical properties of the final compounds, which include selective and non-selective pyridine-ring hydrogenations and a few unexpected side reactions, are described.

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