15290-27-4Relevant academic research and scientific papers
Internal Lewis acid assisted ureas: Tunable hydrogen bond donor catalysts
Nickerson, David M.,Angeles, Veronica V.,Auvil, Tyler J.,So, Sonia S.,Mattson, Anita E.
supporting information, p. 4289 - 4291 (2013/06/04)
The strategic incorporation of internal Lewis acids onto urea scaffolds gives rise to a family of tunable hydrogen bond donor catalysts. The nature of the Lewis acid and associated ligands affects the urea polarization, acidity, and activity in reactions
Boronate urea activation of nitrocyclopropane carboxylates
So, Sonia S.,Auvil, Tyler J.,Garza, Victoria J.,Mattson, Anita E.
supporting information; experimental part, p. 444 - 447 (2012/03/10)
Boronate ureas operate as catalysts for the activation of nitrocyclopropane carboxylates in nucleophilic ring-opening reactions. A variety of amines were found to open the urea-activated nitrocyclopropane carboxylates, generating highly useful nitro ester
Internal Lewis acid assisted benzoic acid catalysis
Auvil, Tyler J.,Mattson, Anita E.
supporting information; experimental part, p. 2173 - 2180 (2012/09/22)
Internal Lewis acid assisted benzoic acid derivatives are introduced as new low-molecular-weight single-hydrogen-bond donor catalysts for the activation of nitroalkenes. Selected 2-borylbenzoic acid derivatives gave good yields of products in the addition of indoles to nitroalkenes. Control experiments suggest that both the internal Lewis acid coordination and the carboxylic acid functionalities are critical to the optimal performance of these catalysts. Georg Thieme Verlag Stuttgart New York.
Internal lewis acid assisted hydrogen bond donor catalysis
So, Sonia S.,Burkett, Julie A.,Mattson, Anita E.
supporting information; experimental part, p. 716 - 719 (2011/04/24)
Boronate ureas are introduced as a new class of noncovalent catalysts for conjugate addition reactions with enhanced activity. Through intramolecular coordination of the urea functionality to a strategically placed Lewis acid, rate enhancements up to 10 t
Synthesis and properties of nucleoside derivatives acylated by chemically stable 2-(trimethylsilyl)benzoyl group
Yamada, Ken,Taguchi, Haruhiko,Ohkubo, Akihiro,Seio, Kohji,Sekine, Mitsuo
experimental part, p. 5928 - 5932 (2009/12/26)
We report the synthesis and properties of nucleoside derivatives acylated by 2-(trimethylsilyl)benzoyl (TMSBz) that proved to be extremely stable under basic conditions when introduced into the 5′-hydroxyl group of thymidine, the 4-amino group of deoxycyt
Dialkylhydrazides for directed orthometalations
Pratt, Scott A.,Goble, Michael P.,Mulvaney, Michael J.,Wuts, Peter G. M.
, p. 3559 - 3562 (2007/10/03)
Dimethylhydrazides are shown to be excellent substrates for the directed orthometalation reaction. The advantage of using the hydrazide is that it is easily removed by treatment with H5IO6 or CuCl2 to give the carboxylic acid under very mild conditions, in contrast to other amides that generally require harshly acidic conditions to achieve hydrolysis. (C) 2000 Elsevier Science Ltd.
Photochemical and acid-catalyzed rearrangements of 4-carbomethoxy-4-methyl-3-(trimethylsilyl)-2,5-cyclohexadien-1-one
Schultz, Arthur G.,Antoulinakis, Evan G.
, p. 4555 - 4559 (2007/10/03)
The synthesis of 4-carbomethoxy-4-methyl-3-(trimethylsilyl)-2,5-cyclohexadien-1-one (1) in 60% overall yield from benzaldehyde is described. Irradiation (366 nm) of 1 in benzene solution gave products of type A photorearrangement; e.g., diastereomers of the 4-(trimethylsilyl)- and 5-(trimethylsilyl)bicyclo[3.1.0]hex-3-en-2-ones 8 and 9. Bicyclohexenones 9a and 9b could not be isolated, but underwent acid-catalyzed protiodesilylative rearrangements on attempted chromatography (silica gel) to give a 1:1 mixture of (E)- and (Z)-4-(carbomethoxymethylmethylene)cyclopent-2-en-1-ones 12 and 13. Irradiation (366 nm) of either 12 or 13 resulted in photoisomerization to a photostationary state that was also a 1:1 mixture. Irradiation of 8a or 8b gave equivalent mixtures of phenols 14 and 15 by way of the type B oxyallyl zwitterion 17. The available experimental evidence suggests that both 9a and 9b undergo regiospecific photorearrangement to phenol 16 with no trace of 3-methyl-4-carbomethoxyphenol (19), the product of ipso substitution of the Me3Si group at C(4). Phenol 15 was isolated in 65% yield from the photoreaction of 1 in benzene with 20 equiv of CF3CO2H. The acid-catalyzed rearrangement of 1 to 3-carbomethoxy-4-methylphenol (21) occurs in 91% yield by way of CO2Me group rearrangement to C(3) to give the Me3Si-stabilized carbocation 23.
