63327-99-1Relevant articles and documents
Phosphorus-Based Organocatalysis for the Dehydrative Cyclization of N-(2-Hydroxyethyl)amides into 2-Oxazolines
Soleymani Movahed, Farzaneh,Foo, Siong Wan,Mori, Shogo,Ogawa, Saeko,Saito, Susumu
, p. 243 - 257 (2021/12/17)
A metal-free, biomimetic catalytic protocol for the cyclization of N-(2-hydroxyethyl)amides to the corresponding 2-oxazolines (4,5-dihydrooxazoles), promoted by the 1,3,5,2,4,6-triazatriphosphorine (TAP)-derived organocatalyst tris(o-phenylenedioxy)cyclotriphosphazene (TAP-1) has been developed. This approach requires less precatalyst compared to the reported relevant systems, with respect to the phosphorus atom (the maximum turnover number (TON) ～30), and exhibits a broader substrate scope and higher functional-group tolerance, providing the functionalized 2-oxazolines with retention of the configuration at the C(4) stereogenic center of the 2-oxazolines. Widely accessible β-amino alcohols can be used in this approach, and the cyclization of N-(2-hydroxyethyl)amides provides the desired 2-oxazolines in up to 99% yield. The mechanism of the reaction was studied by monitoring the reaction using spectral and analytical methods, whereby an 18O-labeling experiment furnished valuable insights. The initial step involves a stoichiometric reaction between the substrate and TAP-1, which leads to the in situ generation of the catalyst, a catechol cyclic phosphate, as well as to a pyrocatechol phosphate and two possible active intermediates. The dehydrative cyclization was also successfully conducted on the gram scale.
A convenient synthesis of 2-oxazolines and 2-benoxazoles with PPh3-DDQ as the dehydrating reagent
Xu, Quancai,Li, Zhengning,Chen, Huiying
experimental part, p. 925 - 932 (2012/01/03)
2-Oxazolines and 2-benoxazoles were synthesized in high yields from acylamino alcohols and acylaminophenols, respectively, with triphenylphosphine- 2,3-dichloro-5,6-dicyanobenzoquinone (PPh3-DDQ) as the dehydrating and activating reagent. The synthesis was accomplished under neutral conditions.
Azodioxy-carbonyl compounds by oxidation of cyclic imines with m-CPBA
Perrone, Serena,Pilati, Tullio,Rosato, Francesca,Salomone, Antonio,Videtta, Valeria,Troisi, Luigino
scheme or table, p. 2090 - 2095 (2011/04/22)
This article reports a simple and efficient synthesis of C-nitroso compounds (azodioxy esters or ketones and oximes) through a double oxidation of cyclic imines (4,5-dihydrooxazoles and 3,4-dihydro-2H-pyrroles) with m-CPBA. C-Nitroso derivatives seem to b
Bromotriphenylphosphonium salt promoted tandem one-pot cyclization to optically active 2-Aryl-1,3-oxazolines
Jiang, Haizhen,Yuan, Shijie,Wan, Wen,Yang, Kun,Deng, Hongmei,Hao, Jian
experimental part, p. 4227 - 4236 (2010/10/04)
Optically active 2-aryl-1,3-oxazolines, such as aromatic carbocycles, heterocycle-binding 4-benzyl (or phenyl)-1,3oxazolines and their 5-benzyl (or phenyl)-l,3-oxazoline isomers were successfully prepared through a bromotriphenylphosphonium salt promoted aziridine ring formation and ring opening sequential process involving tandem one pot cyclization of chiral 2-amino-3-phenylpropanol or 2amino-2-phenylethanol with various aromatic acids in toluene at 90 °C in moderate to excellent yields. The mechanism of this tandem process was also substantiated experimentally.
A facile synthesis of 2-oxazolines using a PPh3-DDQ system
Xu, Quancai,Li, Zhengning
experimental part, p. 6838 - 6840 (2010/04/29)
A facile and efficient synthesis of 2-oxazolines from N-(2-hydroxyethyl)amides using a triphenylphosphine-2,3-dichloro-5,6-dicyanobenzoquinone (PPh3-DQQ) system is described. The reaction proceeds under neutral and mild conditions, and excellent yields are obtained.
β-Amidoaldehydes via oxazoline hydroformylation
Laitar, David S.,Kramer, John W.,Whiting, Bryan T.,Lobkovsky, Emil B.,Coates, Geoffrey W.
supporting information; body text, p. 5704 - 5706 (2010/01/31)
4-Substituted oxazolines, which are readily synthesized from naturally occurring α-amino acids, are converted efficiently and stereospecifically to β-amidoaldehydes in the presence of synthesis gas and catalytic dicobalt octacarbonyl.
Decarboxylative isomerization of N-Acyl-2-oxazolidinones to 2-oxazolines
May, Aaron E.,Willoughby, Patrick H.,Hoye, Thomas R.
, p. 3292 - 3294 (2008/09/20)
(Chemical Equation Presented) N-Acyl-2-oxazolidinones are ring-opened by lithium iodide and decarboxylated in the presence of a mild proton source. Further reaction with an amine base provides 2-oxazolines. The transformation is general for oxazolidinones unsubstituted in the 5 position and occurs under mild conditions (25-50°C). These results complement the existing methods for this transformation by allowing lower temperatures and/or avoiding metal catalysts.
Efficient oxidative synthesis of 2-oxazolines
Schwekendiek, Kirsten,Glorius, Frank
, p. 2996 - 3002 (2008/02/10)
New methodology for the synthesis of variously substituted 2-oxazolines and one dihydrooxazine using aldehydes, amino alcohols, and N-bromosuccinimide as an oxidizing agent is described. This one-pot synthesis is characterized by mild reaction conditions, broad scope, high yields, and its preparative simplicity. Georg Thieme Verlag Stuttgart.
Facile Syntheses of Oxazolines and Thiazolines with N-Acylbenzotriazoles under Microwave Irradiation
Katritzky, Alan R.,Cai, Chunming,Suzuki, Kazuyuki,Singh, Sandeep K.
, p. 811 - 814 (2007/10/03)
Microwave reactions of 2-amino-2-methyl-1-propanol (2) or 2-aminoethanethiol hydrochloride (4) with readily available N-acylbenzotriazoles 1a-j in the presence of SOCl2 produced 2-substituted 2-oxazolines 3a-j in 84-98% yields and 2-substituted
