Results 111 to 120 of about 1,523 (159)

Stereoselective Photoredox Catalyzed (3+3) Dipolar Cycloaddition of Nitrone with Aryl Cyclopropane

Angewandte Chemie, 2023
AbstractBy resorting to the principle of remote activation, we herein demonstrate the first photoredox catalyzed (3+3) dipolar cycloaddition of nitrones with aryl cyclopropanes. Key to the fidelity of the reaction resides in a facile manner of substrate activation by single‐electron transfer (SET) oxidation with photoredox catalysis, and the reaction ...
Yao Xu, Hai‐Xiang Gao, Chengkai Pan, Yue Shi, Chi Zhang, Genping Huang, Chao Feng   +6 more
openaire   +2 more sources

New Parabanate Products by 1, 3-Dipolar Cycloaddition Reaction (‘Criss-Cross’ Cycloaddition)

High Performance Polymers, 1999
New parabanate products containing 1, 3, 5, 7-tetraazabicyclo[3, 3, 0]octane-2, 6-dione are described. The synthesis of αω-diisocyanato-telechelics starting from two diisocyanates having a preformed parabanic unit using a [3+2] dipolar cycloaddition reaction was studied.
Adrian A Caraculacu, Elena Scorţanu, Georgeta Caraculacu   +2 more
openaire   +1 more source

ChemInform Abstract: [2 + 3]Dipolar Cycloadditions of a Monomeric Thioaldehyde.

Chemischer Informationsdienst, 1986
AbstractThiopivalaldehyd (I) liefert mit den Nitronen (II) und (IV), dem Nitriloxid (VI), der Diazoverbindung (VIII) sowie dem Azomethinimin (X) die stabilen [2 + 3]‐Cycloaddukte (III), (V), (VII), (IX) und (XI).
E. VEDEJS, R. G. WILDE
openaire   +1 more source

Trimethylsilyl Triflate-promoted [2+3] Dipolar Cycloaddition of Nitrones with Allyltrimethylsilane

HETEROCYCLES, 1992
3-Alkyl-5-trimethylsilylmethylisoxazolidines are accessible in good yields and at temperatures ≤ 20°C, by the trimethylsilyl triflate-promoted reaction of allyltrimethylsilane with aliphatic nitrones.
Claudio Trombini, Dilip D. Dhavale
openaire   +1 more source

Theory of the Formation and Decomposition of N‐Heterocyclic Aminooxycarbenes through Metal‐Assisted [2+3]‐Dipolar Cycloaddition/Retro‐Cycloaddition

Chemistry – A European Journal, 2013
AbstractThe theoretical background of the formation of N‐heterocyclic oxadiazoline carbenes through a metal‐assisted [2+3]‐dipolar cycloaddition (CA) reaction of nitrones R1CHN(R2)O to isocyanides CNR and the decomposition of these carbenes to imines R1CHNR2 and isocyanates OCNR is discussed.
Alexander S, Novikov, Maxim L, Kuznetsov, Armando J L, Pombeiro   +2 more
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Captodative Alkenes in Concerted 1, 3-Dipolar Cycloadditions

1986
The 1, 3-dipolar cycloaddition of an E-/Z-pair of captodative alkenes to a cyclic aldonitrone is demonstrated to occur stereospecifically. Additions of α-(tert-butylthio)acrylonitri le to a series of C, N-diphenylnitrones show a change in regioselectivity upon donor substitution in the C-phenyl-ring.
Dietrich Döpp, Jutta Walter, Sabine Holz   +2 more
openaire   +1 more source

Ti(IV) promoted 1, 3-dipolar cycloaddition of nitrones to vinyl ethers

Tetrahedron, 1998
Abstract The 1, 3-dipolar cycloaddition of nitrones to vinyl ethers is accelerated by Ti(IV) species. The efficiency of the catalyst parallels its complexation capacity. The use of Ti(iPrO)2Cl2 favours the formation of trans cycloadducts, presumably through an endo bidentate complex, in which the metal atom is simultaneously coordinated to the vinyl ...
Pau Bayo´n, Pedro de March, Marta Figueredo, Josep Font   +3 more
openaire   +1 more source

A THEORETICAL STUDY ON THE MECHANISM OF 2:1 1, 3 DIPOLAR CYCLOADDITION REACTIONS

Journal of Theoretical and Computational Chemistry, 2007
The reactions between nitrile oxides and alkenes are of considerable interest in organic synthesis as the resulting heterocycles are versatile intermediates for the synthesis of natural products and biologically active compounds. In this paper, we design a series of reactions of phosphonyl nitrile oxides with acrylonnitrile, which can give 2:1 ...
Wang, J. F., Wei, D. Q., Wang, C. F., Ye, Y., Li, Y. X., Luo, Y., Wang, W. W., Liu, L. Z., Zhao, Y. F.   +8 more
openaire   +1 more source

l,3-Dipolar cycloaddition of unsatu rated ferrocene derivatives with carbonitrileN-oxides

Russian Chemical Bulletin, 1994
3,5-Disubstituted isoxazolines and isoxazoles have been synthesized using 1,3-dipolar cycloaddition of ferrocene derivatives FcCH=CH2, FcCOCH=CH2 and FcC≡CH with aliphatic and aromatic carbonitrileTV-oxides.
G. A. Shvekhgeimer, M Litim
openaire   +1 more source

One-Pot Sequential [3 + 3] Dipolar Cycloaddition of Aldehyde or Ketone and Hydroxylamine with Spirocyclopropyl Oxindole

The Journal of Organic Chemistry, 2018
A Sc(OTf)3-catalyzed highly diastereoselective one-pot sequential [3 + 3] dipolar cycloaddition reaction of aldehyde or ketone, N-alkyl hydroxylamine, and spirocyclopropyl oxindole is developed, allowing facile construction of spirocyclic oxindole-tetrahydro-1,2-oxazines with sufficient structural diversity. The corresponding catalytic enantioselective
Peng-Wei Xu, Chen Chen, Jia-Kuan Liu, Yu-Ting Song, Feng Zhou, Jun Yan, Jian Zhou   +6 more
openaire   +2 more sources