5202-77-7Relevant academic research and scientific papers
Cesium hydroxide-mediated regio- and stereoselective hydroamidation of internal aryl alkynes with primary amides
Yamamoto, Chiaki,Hirano, Koji,Miura, Masahiro
supporting information, p. 1048 - 1050 (2017/06/28)
A cesium hydroxide-mediated hydroamidation of internal aryl alkynes with primary amides has been developed. The reaction proceeds with high anti-selectivity to deliver the corresponding stereodefined (Z)-enamides in good yields. The alkali base-promoted system is also compatible with unsymmetrical aryl alkyl alkynes, and the hydroamidated products are obtained with high regioselectivity as well as stereoselectivity.
Iodine(III)-promoted synthesis of oxazoles through oxidative cyclization of N -styrylbenzamides
Hempel, Christian,Nachtsheim, Boris J.
supporting information, p. 2119 - 2123 (2013/10/21)
The hypervalent iodine reagent PhI(OTf)2, generated in situ, has been successfully utilized in an intramolecular oxidative cyclization of N-styrylbenzamides. In remarkably short reaction times, the desired 2,5-disubstituted oxazoles were isolated in high yields in this metal-free oxidative C-O bond-forming reaction. Georg Thieme Verlag Stuttgart, New York.
Copper-catalyzed cross-coupling of amides and potassium alkenyltrifluoroborate salts: A general approach to the synthesis of enamides
Boishan, Yuri,Batey, Robert A.
experimental part, p. 5283 - 5294 (2010/08/07)
Potassium alkenyltrifluoroborate salts undergo coupling with amides to give enamides using a catalytic amount of Cu(OAc)2 under mild oxidative conditions. The air and water stable alkenyltrifluoroborate salts offer a practical alternative to the use of alkenyl halides and alkenylboronic acids as cross-coupling partners. A range of amides participate in the cross-coupling, including heterocyclic amides, imides, carbamates, benzamides, and acetamides. Optimization studies established two sets of conditions, best suited to either high PKa or low PKa amide substrates. Lower PK amide substrates worked best using a dichloromethane solvent system in the presence of 4 ? molecular sieves, 10 mol % Cu(OAc)2, and 20 mol % N-methylimidazole. Higher PKa amide substrates worked best using a ligandless protocol using a 1:1 dichloromethane/DMSO solvent system in the presence of 4 ? molecular sieves and 10 mol % Cu(OAc)2. The cross-coupling reactions occur stereospecifically with retention of alkene configuration from the alkenyltrifluoroborate salt. The mild reaction conditions employed are tolerant of various functionalities, including nitro, acetals, alkyl and aryl halides, and α,β-unsaturated carbonyls. Finally, the importance of copper sources and the presence of minor impurities were investigated.
Synthesis of secondary enamides by ruthenium-catalyzed selective addition of amides to terminal alkynes
Goossen, Lukas J.,Salih, Kifah S. M.,Blanchot, Mathieu
supporting information; experimental part, p. 8492 - 8495 (2009/05/11)
(Chemical Equation Presented) Enamides made easy: A catalyst system generated in situ using bis(2-methallyl)-(cycloocta-1,5-diene)ruthenium(II), 1,4-bis(dicyclohexylphosphino)butane, and ytterbium triflate efficiently catalyzes the addition of primary amides to terminal alkynes, selectively forming the Z-anti-Markovnikov enamides. The E isomers are also accessible by combining the hydroamidation with an in situ double-bond isomerization reaction.
Enamide synthesis by copper-catalyzed cross-coupling of amides and potassium alkenyltrifluoroborate salts
Bolshan, Yuri,Batey, Robert A.
, p. 2109 - 2112 (2008/12/23)
(Chemical Equation Presented) A new partner: Potassium alkenyltrifluoroborate salts undergo coupling with amides to give enamides in the presence of a Cu(OAc)2 catalyst and under mild oxidative conditions (see scheme). The air- and water-stable alkenyltrifluoroborate salts offer a convenient alternative to alkenyl halides as cross-coupling partners. A range of amides undergo coupling including cyclic amides, imides, and carbamates as well as benzamides.
Novel cobalt-catalyzed carbonylation of 2-aryl-2-oxazolines
Xu, Hongyu,Jia, Li
, p. 1575 - 1577 (2007/10/03)
(Matrix presented) Catalytic ring-expanding carbonylation of 2-aryl-2-oxazolines is reported as a novel method for the synthesis of 4,5-dihydro-1,3-oxazin-6-ones. Various observations suggest the involvement of cobalt radicals as the catalytically active
Stereoselective synthesis of enamides by a Peterson reaction manifold
Fuerstner, Alois,Brehm, Christof,Cancho-Grande, Yolanda
, p. 3955 - 3957 (2007/10/03)
equation presented Vinylsilanes are converted into enamides by a sequence comprising epoxidation, nucleophilic ring opening of the resulting epoxysilanes with NaN3, and reduction of the azide, followed by a "one-pot" N-acylation/Peterson elimin
A novel route to N-styrylamides
Katritzky,Ignatchenko,Lang
, p. 1197 - 1204 (2007/10/02)
A general synthesis of N-styrylamides starting from amides and phenylacetaldehyde is described. Condensation of the amide, aldehyde and benzotriazole affords N-(1-benzotriazol-1-yl-2-phenylethyl)amides 2 from which the benzotriazole molecule is smoothly eliminated.
