Results 201 to 210 of about 24,842 (217)

The Reactivity of Addends in the 1,3-Dipolar Cycloaddition Reaction

Russian Chemical Reviews, 1984
The influence of donor-acceptor interactions and localisation energies on the reactivity of addends in the 1,3-dipolar cycloaddition reaction is examined. It is shown that the interactions between the symmetric frontier orbitals and between the antisymmetric frontier orbitals are qualitatively different in (4π+2π)-cycloaddition reactions.
Samuilov Y., Konovalov A.
openaire   +4 more sources

Experimental and Theoretical DFT Study on Synthesis of Sterically Crowded 2,3,3,(4)5‐Tetrasubstituted‐4‐nitroisoxazolidines via 1,3‐Dipolar Cycloaddition Reactions Between Ketonitrones and Conjugated Nitroalkenes

, 2016
1,3-Dipolar cycloaddition reactions between ketonitrones (1a, 1b, 1c, 1d, 1e) and β-substituted nitroalkenes (2a, 2b, 2c, 2d) proceed under mild conditions, with complete regioselectivity, and lead with high yields to sterically crowded 2,3,3,5 ...
R. Jasiński, Kamil Mróz, Agnieszka Kącka   +2 more
semanticscholar   +1 more source

Asymmetric Synthesis of 2′‐Trifluoromethylated Spiro‐pyrrolidine‐3,3′‐oxindoles via Squaramide‐Catalyzed Umpolung and 1,3‐Dipolar Cycloaddition

, 2016
The introduction of a trifluoromethyl group into the 2-position of spiro-pyrrolidine-3,3-oxindoles is described. By using 1mol% of a quinine-derived squaramide as catalyst, the 2,2,2-trfluoroethylamine (CF3CH2NH2)-derived ketimine is transformed ...
Jinhuan Su, Zelin Ma, Xiaoyuan Li, Li Lin, Zhiqiang Shen, Peiju Yang, Yuan Li, Hailin Wang, Wenjin Yan, Kairong Wang, Rui Wang   +10 more
semanticscholar   +1 more source

Click chemistry reactions in medicinal chemistry: Applications of the 1,3‐dipolar cycloaddition between azides and alkynes

Medicinal research reviews (Print), 2008
G. Tron, T. Pirali, R. Billington, P. Canonico, G. Sorba, A. Genazzani   +5 more
semanticscholar   +1 more source

Concertedness of 1,3-dipolar cycloadditions

Journal of Chemical Education, 1984
The 1,3-dipolar cycloaddition is the union of a 1,3-dipole with a multiple bond system (a dipolarophile) to form a five-membered ring; the process is regarded as one of the most general methods for the synthesis of five-membered heterocycles.
openaire   +2 more sources

Toward the Briarane Core via 1,3-Dipolar Cycloaddition

Organic Letters
The complete C20 framework of brianthein W was established, featuring hydroboration/allylation, to provide the C1-C2 quaternary/tertiary stereoarray with excellent stereocontrol. Intramolecular nitrile oxide cycloaddition (INOC) was adopted as the key transformation to establish the trans-fused 6/10-bicyclic ring system.
Yichen Liu, Jiangang Zhao, Ran Hong
openaire   +2 more sources

1,3-dipolar cycloadditions with porphyrins

2001
The objective of this work is to use 1,3-dipolar cycloadditions to synthesize novel aromatic compounds based on meso-phenyl substituted porphyrins. These compounds are potential photosensitizers for use in photodynamic therapy. Tetraphenylporphyrins with a variety of substituents were reacted with selected 1,3-dipoles.
openaire   +2 more sources

1,3-Dipolar Cycloaddition

2002
G. Hajos, Z. Riedl
openaire   +1 more source

1,3-Dipolar Cycloadditions to Oxidopyraziniums

HETEROCYCLES, 1995
John A. Joule, Nicholas D. Yates, David A. Peters, Philip A. Allway, Roy L. Beddoes, David I. C. Scopes   +5 more
openaire   +1 more source

1,3-Dipolar cycloaddition reactions of azomethine ylides and alkynes

Chemistry of Heterocyclic Compounds, 2018
A. Gulevskaya, Julia I. Nelina-Nemtseva
semanticscholar   +1 more source