Results 21 to 30 of about 596,435 (207)

Triphenylborane in Metal-Free Catalysis

Molecules, 2023
The development and application of new organoboron reagents as Lewis acids in synthesis and metal-free catalysis have dramatically expanded over the past 20 years. In this context, we will show the recent uses of the simple and relatively weak Lewis acid BPh3—discovered 100 years ago—as a metal-free catalyst for various organic transformations.
Suresh Mummadi, Clemens Krempner
openaire   +3 more sources

An efficient metal-free and catalyst-free C–S/C–O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides

Beilstein Journal of Organic Chemistry, 2023
An operationally simple and metal-free approach is described for the synthesis of pyrazole-tethered thioamide and amide conjugates. The thioamides were generated by employing a three-component reaction of diverse pyrazole C-3/4/5 carbaldehydes, secondary
Shubham Sharma, Dharmender Singh, Sunit Kumar, Vaishali, Rahul Jamra, Naveen Banyal, Deepika, Chandi C. Malakar, Virender Singh   +8 more
doaj   +1 more source

How Very Massive Metal Free Stars Start Cosmological Reionization [PDF]

, 2007
(Abridged) Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include non-equilibrium primordial gas chemistry
Abel, Tom, Wise, John H.
core   +3 more sources

Metal-Free Chlorodeboronation of Organotrifluoroborates [PDF]

The Journal of Organic Chemistry, 2011
A mild and metal-free method for the chlorodeboronation of organotrifluoroborates using trichloroisocyanuric acid (TCICA) was developed. Aryl-, heteroaryl-, alkenyl-, alkynyl-, and alkyltrifluoroborates were converted into the corresponding chlorinated products in good yields. This method proved to be tolerant of a broad range of functional groups.
Gary A, Molander, Livia N, Cavalcanti
openaire   +2 more sources

Photodissociative Regulation of Star Formation in Metal-Free Pregalactic Clouds [PDF]

, 1999
We study the H2 photodissociation regions around OB stars in primordial gas clouds whose virial temperatures are between a few hundred and a few thousand Kelvin. In such small objects, a single O star can photodissociate a mass equal to that of the cloud
Couchman H. M. P., de Jong T., Fukugita M., Kazuyuki Omukai, Martin P. G., Ryoichi Nishi   +5 more
core   +2 more sources

Metal-free synthesis of 3-trifluoromethyl-1,2,4-triazoles via multi-component reaction of trifluoroacetimidoyl chlorides, hydrazine hydrate and benzene-1,3,5-triyl triformate

Frontiers in Chemistry, 2022
A convenient approach for the construction of pharmaceutically valuable 3-trifluoromethyl-1,2,4-triazoles has been developed, which employs the readily available trifluoroacetimidoyl chlorides, hydrazine hydrate and benzene-1,3,5-triyl triformate (TFBen)
Binjie Wang, Yue Sun, An Cheng, Yeanlun Zhu, Jiye Wang, Zhengkai Chen, Xiao-Feng Wu, Xiao-Feng Wu   +7 more
doaj   +1 more source

Star Formation in the First Galaxies I: Collapse Delayed by Lyman-Werner Radiation [PDF]

, 2012
We investigate the process of metal-free star formation in the first galaxies with a high-resolution cosmological simulation. We consider the cosmologically motivated scenario in which a strong molecule-destroying Lyman-Werner (LW) background inhibits ...
Abel, Abel, Ahn, Ahn, Anshu Dubey, Bader, Barkana, Bate, Bate, Beers, Begelman, Bergin, Bertschinger, Bonazzola, Bonnor, Bromm, Bromm, Bromm, Bromm, Bromm, Bromm, Cen, Chalence Safranek-Shrader, Chandrasekhar, Cho, Christoph Federrath, Ciardi, Ciardi, Clark, Clark, Colella, Collins, Couchman, Dijkstra, Draine, Dubey, Dubey, Dubey, Ebert, Eisenstein, Elmegreen, Evans, Federrath, Federrath, Federrath, Federrath, Federrath, Ferrara, Flower, Frebel, Frisch, Fryxell, Fumagalli, Furlanetto, Galli, Gammie, Gardner, Girichidis, Glover, Glover, Glover, Glover, Goldreich, Greif, Greif, Greif, Greif, Greif, Greif, Haiman, Haiman, Haiman, Heger, Hennebelle, Hennebelle, Holzbauer, Hosokawa, Hummel, Inoue, Johnson, Johnson, Kainulainen, Klessen, Kolmogorov, Komatsu, Kratter, Kritsuk, Kritsuk, Kritsuk, Krumholz, Krumholz, Krumholz, Krumholz, Latif, Latif, Mac Low, Machacek, Maio, McGreer, McKee, McKee, Meghann Agarwal, Mesinger, Miloš Milosavljević, Molina, Nelson, O'Shea, O'Shea, O'Shea, Oh, Oh, Omukai, Omukai, Omukai, Osterbrock, Ostriker, Padoan, Padoan, Padoan, Padoan, Palla, Pan, Passot, Press, Price, Price, Prieto, Prieto, Prunet, Regan, Ricker, Ricotti, Rydberg, Safranek-Shrader, Scalo, Scannapieco, Schaerer, Schneider, Shang, Shapiro, Sheth, Solomon, Stacy, Stacy, Stahler, Stecher, Stiavelli, Tanaka, Tegmark, Toomre, Tornatore, Trenti, Trenti, Truelove, Turk, Vazquez-Semadeni, Volker Bromm, Wang, Wise, Wise, Wise, Wise, Wolcott-Green, Wolcott-Green, Yoshida, Yoshida, Zackrisson, Zuckerman   +167 more
core   +2 more sources

Mechanical Factors Implicated in Zirconia Implant Fracture Placed within the Anterior Region—A Systematic Review

Dentistry Journal, 2022
Background: To analyze the fracture resistance of zirconia implants within the anterior region and evaluate whether zirconia–zirconia implants can be a viable alternative to titanium implants.
Lauryn Attard, Victoria Lee, Jennifer Le, Chloe Lowe, Vipra Singh, Jacky Zhao, Dileep Sharma   +6 more
doaj   +1 more source

Metal Free Phosphorus Butterfly Compounds

European Journal of Inorganic Chemistry, 2020
AbstractMetal‐free organophosphorus are demanded compounds due to their interesting properties in a variety of applications, spanning from fine to material chemistry. Unfortunately, their synthesis is very challenging, requiring a precise design of the reaction conditions to avoid the conspicuous formation of undesired products.
Franco Scalambra, Antonio Romerosa
openaire   +2 more sources

Synthesis of 2H-Chromenones from Salicylaldehydes and Arylacetonitriles

Molecules, 2017
An efficient and convenient protocol for the synthesis of 2H-chromenones has been developed. In the presence of tBuOK in DMF, good to excellent yields of various chromenones were obtained from the corresponding salicylaldehydes and arylacetonitriles.
Chengcai Li, Hailin Zhu, Hang Zhang, Yongfeng Yang, Feng Wang   +4 more
doaj   +1 more source