Results 31 to 40 of about 8,699 (217)

Nanoparticle‐Catalysed 1,3‐Dipolar Cycloadditions

European Journal of Organic Chemistry, 2020
The 1,3‐dipolar cycloadditions of azomethine‐ylides and ‐imines, nitrones, nitrilimines, and azides catalysed by inorganic nanoparticles are described. Emphasis is given to the nanometric catalysts involved, their structure, characterisation, and recyclability and, when remarkable, their preparation.
Ponti A., Molteni G.
openaire   +3 more sources

Concerted [4 + 2] and Stepwise (2 + 2) Cycloadditions of Tetrafluoroethylene with Butadiene: DFT and DLPNO-UCCSD(T) Explorations. [PDF]

, 2020
Tetrafluoroethylene and butadiene form the 2 + 2 cycloadduct under kinetic control, but the Diels-Alder cycloadduct is formed under thermodynamic control. Borden and Getty showed that the preference for 2 + 2 cycloaddition is due to the necessity for syn-
Houk, KN, Liu, Peng, Mackey, Joel L, Pemberton, Ryan P, Svatunek, Dennis   +4 more
core  

Azetidinylideneketenimines as a Multimodal Synthetic Platform: Coordination Chemistry and Cycloaddition‐Triggered Transformations

Angewandte Chemie, EarlyView.
Cross‐coupling/homologation sequence between a stable three‐membered‐ring carbene and isocyanides enables facile and rapid access to novel methyleneketenimines and the first bis(methyleneketenimine). Reactivity studies gave rise to the first methyleneketenimine‐transition metal complexes, unique multimodal reactivity ranging from CO2, isocyanate ...
Taichi Koike, Keisuke Ito, Shintaro Ishida, Takeaki Iwamoto   +3 more
wiley   +2 more sources

Kinetic and Thermodynamic Approaches for the Efficient Formation of Mechanical Bonds [PDF]

, 2008
Among the growing collection of molecular systems under consideration for nanoscale device applications, mechanically interlocked compounds derived from electrochemically switchable bistable [2]rotaxanes and [2]catenanes show great promise. These systems
Aprahamian, Ivan, Dichtel, William R., Heath, James R., Miljanić, Ognjen Š., Patel, Kaushik, Spruell, Jason M., Stoddart, J. Fraser, Zhang, Wenyu   +7 more
core   +1 more source

The [4+2]‐Cycloaddition of α‐Nitrosoalkenes with Thiochalcones as a Prototype of Periselective Hetero‐Diels–Alder Reactions—Experimental and Computational Studies [PDF]

, 2020
The [4+2]‐cycloadditions of α‐nitrosoalkenes with thiochalcones occur with high selectivity at the thioketone moiety of the dienophile providing styryl‐substituted 4H‐1,5,2‐oxathiazines in moderate to good yields.
Boger D. L., Carruthers W., Corey E. J., Fleming I., Huisgen R., Huisgen R., Reissig H.-U., Warren S., Zweifel G. S.   +8 more
core   +1 more source

Copper nanoparticles on controlled pore glass (CPG) as highly efficient heterogeneous catalysts for “click reactions”

Scientific Reports, 2020
We herein report that supported copper nanoparticles (CuNPs) on commercially available controlled pore glass (CPG), which exhibit high mechanical, thermal and chemical stability as compared to other silica-based materials, serve as a useful heterogeneous
Abdolrahim A. Rafi, Ismail Ibrahem, Armando Córdova   +2 more
doaj   +1 more source

Asymmetric 1,3-Dipolar Cycloadditons of Stabilized Azomethine Ylides with Nitroalkenes [PDF]

, 2014
This review highlights the biological importance of many polysubstituted nitro-prolines and -pyrrolidines. Their preparation using asymmetric 1,3-dipolar cycloadditions of azomethine ylides with nitroalkenes using diastereoselective and enantioselective ...
Nájera, Carmen, Sansano, Jose M.
core   +2 more sources

Solvent-Free 1,3-Dipolar Cycloadditions of Nitrones for a More Sustainable Synthesis of Glycomimetics

Reactions
1,3-Dipolar cycloadditions on nitrone dipoles are key reactions to access five-membered heterocycles, which are useful intermediates in the synthesis of biologically relevant glycomimetics.
Debora Pratesi, Alessio Morano, Andrea Goti, Francesca Cardona, Camilla Matassini   +4 more
doaj   +1 more source

X=Y–ZH compounds as potential 1,3-dipoles. Part 64: Synthesis of highly substituted conformationally restricted and spiro nitropyrrolidines via Ag(I) catalysed azomethine ylide cycloadditions [PDF]

, 2008
1,3-Dipolar reactions of imines of both acyclic and cyclic α-amino esters with a range of nitroolefins using a combination of AgOAc or Ag2O with NEt3 are described.
Albert, Amornraksa, Ayerbe, Becker, Berger, Bourguignon, Bryce, Cecilia Orgaz de la Cierva, Colin Kilner, Crooks, Dondas, Díaz-Ortiz, Fejes, Fejes, Gentles, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, H. Ali Dondas, Hill, Kabalka, Krapcho, Lee, Mohammed A.B. Sarker, Nielson, Norman, Nyerges, Nyerges, Nyerges, Nyerges, Nyerges, Pak, Peterli, Pinna, Poornachandran, Poornachandran, Poornachandran, Ram, Rang, Ronald Grigg, Sader-Bakaouni, Shorter, Song, Thurkauf, Vivanco, Yan   +51 more
core   +1 more source

Kinetic Resolution of Alkylidene Norcamphors via a Ligand-Controlled Umpolung-Type 1,3-Dipolar Cycloaddition

iScience, 2019
Summary: Development of a general catalytic and highly efficient method utilizing readily available precursors for the regio- and stereoselective construction of bioactive natural-product-inspired spiro architectures remains a formidable challenge in ...
Chong Shen, Yuhong Yang, Liang Wei, Wu-Wei Dong, Lung Wa Chung, Chun-Jiang Wang   +5 more
doaj   +1 more source