30160-48-6Relevant academic research and scientific papers
Ruthenium-Catalyzed Oxidative Amidation of Alkynes to Amides
álvarez-Pérez, Andrea,Esteruelas, Miguel A.,Izquierdo, Susana,Varela, Jesús A.,Saá, Carlos
supporting information, p. 5346 - 5350 (2019/07/08)
Complex CpRuCl(PPh3)2 catalyzes reactions of terminal alkynes with 4-picoline N-oxide and primary and secondary amines to afford the corresponding amides. The reactions occur in chlorinated solvent and aqueous medium, showing applications in peptide chemistry. Stoichiometric studies reveal that the true catalysts of the processes are the vinylidene cations [CpRu(=C=CHR)(PPh3)2]+ which are oxidized to the Ru(η2-CO)-ketenes by the N-oxide. Finally, nucleophilic additions of primary and secondary amines to the free ketenes yield the corresponding amides.
Preparation of Heterocycles via Visible-Light-Driven Aerobic Selenation of Olefins with Diselenides
Zhang, Qing-Bao,Yuan, Pan-Feng,Kai, Liang-Lin,Liu, Kai,Ban, Yong-Liang,Wang, Xue-Yang,Wu, Li-Zhu,Liu, Qiang
supporting information, p. 885 - 889 (2019/02/14)
The aerobic dehydrogenative cyclization of alkenes with easily accessible diselenides facilitated by visible light is reported. Notably, the features of this transition-metal-free protocol are pronounced efficiency and practicality, good functional group
Sterically Demanding Oxidative Amidation of α-Substituted Malononitriles with Amines Using O2
Li, Jing,Lear, Martin J.,Hayashi, Yujiro
supporting information, p. 9060 - 9064 (2016/07/26)
An efficient amidation method between readily available 1,1-dicyanoalkanes and either chiral or nonchiral amines was realized simply with molecular oxygen and a carbonate base. This oxidative protocol can be applied to both sterically and electronically challenging substrates in a highly chemoselective, practical, and rapid manner. The use of cyclopropyl and thioether substrates support the radical formation of α-peroxy malononitrile species, which can cyclize to dioxiranes that can monooxygenate malononitrile α-carbanions to afford activated acyl cyanides capable of reacting with amine nucleophiles.
Ammonium nitrate: A biodegradable and efficient catalyst for the direct amidation of esters under solvent-free conditions
Ramesh, Perla,Fadnavis, Nitin W.
supporting information, p. 138 - 140 (2015/02/19)
A simple, metal-free, and environment-friendly procedure is developed for the direct conversion of esters to amides using ammonium nitrate as a catalyst under solvent-free conditions. Aryls, heteroaryls, and aliphatic esters are easily converted to the corresponding amides in excellent isolated yields (85-99%). An enantiopure ester and amine were both shown to react without racemization. The methodology has been successfully applied to preparation of procainamide.
Umpolung Amide Synthesis using substoichiometric N-iodosuccinimide (NIS) and oxygen AS a terminal oxidant
Schwieter, Kenneth E.,Shen, Bo,Shackleford, Jessica P.,Leighty, Matthew W.,Johnston, Jeffrey N.
supporting information, p. 4714 - 4717 (2015/04/27)
Umpolung Amide Synthesis (UmAS) provides direct access to amides from an α-bromo nitroalkane and an amine. Based on its mechanistic bifurcation after convergent C-N bond formation, depending on the absence or presence of oxygen, UmAS using substoichiometric N-iodosuccinimide (NIS) under aerobic conditions has been developed. In combination with the enantioselective preparation of α-bromo nitroalkane donors, this protocol realizes the goal of enantioselective α-amino amide and peptide synthesis based solely on catalytic methods.
Amide formation using in situ activation of carboxylic acids with [Et 2NSF2]BF4
Mahe, Olivier,Desroches, Justine,Paquin, Jean-Francois
, p. 4325 - 4331 (2013/07/26)
The formation of amides through the in situ activation of carboxylic acids with [Et2NSF2]BF4 is presented. A wide range of carboxylic acids and amines were used to produce the corresponding amides in up to 99 % yield. The reaction of hindered amines was also possible in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under slightly modified conditions. An enantiopure carboxylic acid and amine were both shown to react without racemization. Copyright
KAl(SO4)2.12H2O as an eco-friendly and reusable catalyst for the synthesis of amides by the Ritter reaction
Sadeghi, Bahareh,Farahzadi, Ebrahim,Hassanabadi, Alireza
, p. 539 - 540 (2012/10/30)
KAl(SO4)2.12H2O (Alum) is an eco-friendly, inexpensive, readily available and reusable and was applied as catalyst to the synthesis of N-alkyl amides from nitriles and alcohols by the Ritter reaction. This solvent-free procedure is very simple with excellent yields and easy work-up.
Umpolung reactivity in amide and peptide synthesis
Shen, Bo,Makley, Dawn M.,Johnston, Jeffrey N.
experimental part, p. 1027 - 1032 (2011/08/06)
The amide bond is one of natureg€s most common functional and structural elements, as the backbones of all natural peptides and proteins are composed of amide bonds. Amides are also present in many therapeutic small molecules. The construction of amide bonds using available methods relies principally on dehydrative approaches, although oxidative and radical-based methods are representative alternatives. In nearly every example, carbon and nitrogen bear electrophilic and nucleophilic character, respectively, during the carbong€"nitrogen bond-forming step. Here we show that activation of amines and nitroalkanes with an electrophilic iodine source can lead directly to amide products. Preliminary observations support a mechanism in which the polarities of the two reactants are reversed (German, umpolung) during carbong€"nitrogen bond formation relative to traditional approaches. The use of nitroalkanes as acyl anion equivalents provides a conceptually innovative approach to amide and peptide synthesis, and one that might ultimately provide for efficient peptide synthesis that is fully reliant on enantioselective methods.
Efficient radical cyclisation of secondary amides: An enantioselective synthesis of phenyl allokainoid
Bryans, Justin S.,Large, Jonathan M.,Parsons, Andrew F.
, p. 3487 - 3490 (2007/10/03)
Cyclisation of various unsaturated haloamides with tributyltin hydride/AIBN has been explored. Substituted pyrrolidinones were isolated in good to excellent yield and the cyclisation of a serine-derived amide was utilised as the key step in an enantiosele
Efficient tin hydride-mediated radical cyclisation of secondary amides. Part 1. Synthesis of a variety of substituted pyrrolidinones
Bryans, Justin S.,Large, Jonathan M.,Parsons, Andrew F.
, p. 2897 - 2904 (2007/10/03)
The tin hydride-mediated 5-exo-trig cyclisation of a variety of secondary haloamides under mild, neutral reaction conditions has been investigated. Cyclisation was found to produce substituted pyrrolidinones in good to reasonable yield when the reaction was carried out in boiling toluene; lower yields were observed when using boiling benzene. The predominant formation of the lrans-(C-3-C-4) isomers is consistent with a reversible cyclisation leading to the thermodynamically more stable product. The nature of the acceptor carbon-carbon double bond and substituents at the radical centre were found to influence the stereoselectivity of the cyclisation: more of the c/5-isomer was isolated from precursors bearing a radical stabilising group on the alkene. This can be explained by a slower radical ring opening (or fragmentation) reaction leading to more of the kinetic (cis) product. The introduction of substituents alpha to nitrogen (which can influence the amide conformer population) improved the yield of cyclisation and substituted pyrrolidinones could be isolated in up to 76% yield. The Royal Society of Chemistry 1999.
