135906-34-2Relevant articles and documents
Palladium-Catalyzed Divergent Imidoylative Cyclization of Multifunctionalized Isocyanides: Tunable Access to Oxazol-5(4 H)-ones and Cyclic Ketoimines
Wang, Jian,Zhong, Ling,Tang, Shi,Liu, Yuan,Ding, Shumin,Li, Lianjie,Zhao, Haixia,Chen, Chen,Shang, Yongjia
, p. 7297 - 7308 (2020)
A palladium-catalyzed tunable imidoylative cyclization of multifunctionalized isocyanides to construct diverse imine-containing heterocycles has been developed. Oxazol-5(4H)-one derivatives were obtained exclusively when allyl-2-benzyl(or allyl)-2-isocyanoacetates were used in the reaction with aryl triflates as electrophiles, whereas cyclic ketoimines were generated in the presence of aryl iodides with the allyl ester group remaining unreacted. The reactions proceeded smoothly under mild conditions with a wide functional group tolerance.
BEMP-promoted C(4)-alkylation of 4-alkyloxazol-5(4 H)-ones: A rapid and efficient route to α,α-dialkyl-α-amino acids
Lee, Yeon-Ju,Seo, Jeyoung,Kim, Dong-Guk,Park, Hyeung-Geun,Jeong, Byeong-Seon
, p. 701 - 704 (2013/05/09)
Rapid and efficient C(4)-alkylation of 4-alkyloxazol-5(4H)-ones has been achieved by the utilization of BEMP as base. 4,4-Dialkyloxazol-5(4H)-ones, which can easily be hydrolyzed into free α,α-dialkyl-α-amino acids, were obtained in high yields (up to 99%
Synthesis of N-acyl-N,alpha,alpha-trialkyl and N-acyl-alpha,alpha-dialkyl glycines by selective cleavage of Ugi-Passerini adducts. Qualitative assessment of the effect of substituents on the path and yield of reaction.
Jiang, Wei-Qun,Costa, Susana P G,Maia, Hernani L S
, p. 3804 - 3810 (2007/10/03)
Several symmetric N-acyl-N,alpha,alpha-trialkyl glycine amides were synthesised by the Ugi-Passerini four-component reaction and subjected to selective cleavage with trifluoroacetic acid. In almost all cases it was possible to obtain the corresponding N-acyl-N,alpha,alpha-trialkyl and N-acyl-alpha,alpha-dialkyl glycines in fair to good yields directly from the reaction adducts. With some of the bulkier compounds our results show that the selectivity of cleavage is concentration dependent with respect to the acid, which suggests kinetically controlled processes. The isolation of a stable oxazolone as the product of some of the reactions seems to confirm that amide cleavage involves in all cases formation of an oxazolone-type derivative.
An Unexpected Ring Enlargemant of 3-(Dimethylamino)-2,2-dimethyl-2H-azirine to 4,5-Dihydropyridin-2(3H)-one Derivatives
Hugener, Martin,Heimgartner, Heinz
, p. 1863 - 1878 (2007/10/02)
The reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine (1a) and 4,4-disubstituted 2-(trifluoromethyl)-1,3-oxazol-5(4H)-ones 7 in MeCN at 70 deg afforded 5-(dimethylamino)-3,6-dihydropyrazin-2(1H)-ones 10 (Scheme 4), whereas no reaction could be observed between 1a and 2-allyl-4-phenyl-2-(trifluoromethyl)-1,3-oxazol-5(2H)-one (8a) or 4,4-dibenzyl-2-phenyl-1,3-oxazol-5(4H)-one (9).The formation of 10 is rationalized by a mechanism via nucleophilic attack of 1a onto 7.The failure of a reaction with 9 shows that only activated 1,3-oxazol-5(4H)-ones bearing electron-withdrawing substituents do react as electrophiles with 1a.The amino-azirine 1a and 2,4-disubstituted 1,3-oxazol-5(4H)-ones 2b-e in refluxing MeCN undergo a novel ring enlargement to 4,5-dihydropyridin-2(3H)-ones 11 (Scheme 5).Several side products were observed in these reactions.Two different reaction mechanisms for the formation of 11 are proposed: either 1a undergoes a nucleophilic addition onto the open-chain ketene tautomer of 2 (Scheme 6), or 2 reacts as CH-acidic compound (Scheme 7).
SYNTHESIS OF α-SUBSTITUTED α-AMINO ACIDS BY THE ALKYLATION OF 5-OXAZOLINONE DERIVATIVES
Slavinskaya, V. A.,Sile, D. E.,Katkevich, M. Yu.,Korchagova, E. Kh.,Lukevits, E.
, p. 724 - 728 (2007/10/02)
Methods have been developed for the alkylation of 5-oxazolinone derivatives in DMF in the presence of K2CO3, KOH, or diisopropylethylamine and a phase transfer catalyst as well as for the preparation of α-methylphenylalanine, α-methylalanine, α-methylalanine, and the methyl ester of N-benzoyl-α-methylalanine.Increasing the initial concentration of the starting 5-oxazolinone in the reaction mixture leads to a sharp drop in the yield of reaction products due to side condensation reactions.The reaction of 2-phenyl-4-benzyl-5-oxazolinonewith ethyl iodide gave a dimer, mamely, 3-(benzoylamino)-3,5-dibenzylpyrrolidine-2,4-dione.