Results 21 to 30 of about 18,239,073 (189)

1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones [PDF]

, 2010
1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones is described. A series of novel isoxazolines are isolated from the nitrile oxide cycloadditions, whilst the isoxazolines generated from the nitrone cycloadditions ...
Lawrence, Simon E., Kissane, Marie, Maguire, Anita R.   +2 more
core   +1 more source

Highly Enantio‐ and Diastereoselective Synthesis of Tetrahydrofuran Frameworks via Chiral Lewis Acid‐Catalyzed Formal [3+2] Cycloaddition of Allylsilanes

Angewandte Chemie, EarlyView.
The first catalytic asymmetric formal [3+2] cycloaddition of allylsilanes delivers cis‐2,5‐disubstituted tetrahydrofuran‐3‐ones that serve as versatile intermediates for the synthesis of diverse bioactive scaffolds. ABSTRACT A formal [3+2] cycloaddition via cyclization/1,2‐hydride shift initiated by nucleophilic attack of allylsilanes has been ...
Hosung Lee, Dong Kyu Kim, Pingshan Xin, Jin Won Lee, Terim Seo, Do Hyun Ryu   +5 more
wiley   +2 more sources

Synthesis and cytotoxic evaluation of substituted 3-(3′-indolyl-/3′-pyridyl)-isoxazolidines and bis-indoles

Acta Pharmaceutica Sinica B, 2012
Regio- and stereoselective 1,3-dipolar cycloadditions of C-(3-indolyl)-N-phenylnitrone (10) were carried out with different mono-substituted, disubstituted and cyclic dipolarophiles under mono-mode microwave irradiation to obtain substituted 3-(indol-3 ...
Vishal Sharma, Raman Kalia, Tilak Raj, Vivek K. Gupta, Nitasha Suri, Ajit K. Saxena, Deepak Sharma, Surinderjit S. Bhella, Gurpinder Singh, Mohan Paul S. Ishar   +9 more
doaj   +1 more source

A de‐novo Approach Towards Divergent [3+2π/σ] Photocycloadditions of Nitrones via Assembly‐Controlled Kinetic Electron Transfer Gating

Angewandte Chemie, EarlyView.
A metal‐free photocatalytic platform converts nitrones into 4‐isoxazolines and oxa–aza–bicycloheptanes through divergent [3+2π/σ] cycloadditions. Assembly‐controlled kinetic electron transfer gating dictates substrate activation, enabling selective reactivity beyond thermodynamic expectations.
Nayan Saha, Rajesh Kancherla, Jorge Escorihuela, Shana Chandran, Mrinal K. Bera, Magnus Rueping, Burkhard König   +6 more
wiley   +2 more sources

Photo-induced 1, 3-Dipolar Cycloaddition Reaction of Aziridinedicarboximide

Chemical and Pharmaceutical Bulletin, 1969
Cycloaddition reaction of N-(p-methoxyphenyl)-1-benzyl-2, 3-aziridinedicarboximide (8) with dimethyl acetylenedicarboxylate (3) was not effected thermally, but under irradiation it resulted in a formation of 1 : 1-cycloadducts, I (9), II (17), and III (34), and a 1 : 2-cycloadduct IV (38).
OIDA, SADAO, OHKI, EIJI
openaire   +2 more sources

Synthesis of 1,4-Disubstituted Mono and Bis-triazolocarbo-acyclonucleoside Analogues of 9-(4-Hydroxybutyl)guanine by Cu(I)-Catalyzed Click Azide-Alkyne Cycloaddition [PDF]

, 2011
A series of novel mono-1,2,3-triazole and bis-1,2,3-triazole acyclonucleoside analogues of 9-(4-hydroxybutyl)guanine was prepared via copper(I)-catalyzed 1,3-dipolar cycloaddition of N-9 propargylpurine, N-1-propargylpyrimidines/as-triazine with the ...
Krim, Jamal, Taourirte, Mohamed, Engels, Joachim W., Moha Taourirte, Jamal Krim, Joachim W. Engels   +5 more
core   +1 more source

1,3-Dipolar Cycloadditions of Chiral Nitrones [PDF]

, 1989
The asymmetric synthesis of natural products via 1,3-dipolar cycloadditions of chiral nitrones to prochiral olefins has been an area of intense activity over the past decade. The work described in this thesis involves the application of two short, highly
Keirs, David
core   +6 more sources

Farnesyltransferase Enables Modular Assembly of Dual‐Functional Nanobody Conjugates for in Vivo Imaging of Inflammation

Angewandte Chemie, EarlyView.
A modular farnesyltransferase‐based chemoenzymatic platform enables fast, site‐specific labeling of nanobodies for PET imaging of inflammation. CD11b‐targeted PET agents selectively image myeloid‐driven inflammation, while CD45‐targeted PET agents provide sensitive whole‐body immune mapping.
Sneha Venkatachalapathy, Yoon Ho Lee, Ali Salehi Farid, Heydar Moravej, Sina Djafari Rouhani, Jennifer E. Rowley, Mohammad Rashidian, Mark D. Distefano   +7 more
wiley   +2 more sources

TADF‐Active Tetrazole Luminophores for Visible‐Light Functionalization of Nanoparticles and Surfaces

Angewandte Chemie, EarlyView.
A series of tetrazoles are reported that undergo 1,3‐dipolar cycloadditions with alkene and alkyne substrates, generating (dihydro)pyrazole products that exhibit thermally activated delayed fluorescence (TADF). The “photo‐click” reactivity of these tetrazoles is leveraged to functionalize nanoparticles and surfaces with TADF‐active chromophores ...
Ryoga Hojo, Katrina Bergmann, Siyuan L. Xie, Connor S. Durfy, William L. Primrose, Athan T. Gogoulis, Seja A. Elgadi, Mitchell J. Demchuk, Thomas Kalab, Peiqi Hu, Eva M. Nichols, Zachary M. Hudson   +11 more
wiley   +2 more sources

Synthesis of Spiroisoxazolines by 1,3-Dipolar Cycloaddition

Molecules, 1997
The cycloaddition of the chiral nitrile oxide 1 to 1-R-substituted 3,3-methylene-5,5-dimethyl-2-pyrrolidinones 2 (where R is H, n-butyl-, 1,1-dimethylethoxycarbonyl-, 1-methylethenyl- and acetyl-) proceeds regioselectively under the formation of ...
Peter Ertl, Vladimír Ondrus, Lubor Fisera, Peter Micuch   +3 more
doaj   +1 more source