40647-89-0Relevant academic research and scientific papers
Structure-activity relationship of dihydroimidazo-, dihydropyrimido, tetrahydrodiazepino-[2,1-b]-thiazoles, and -benzothiazoles as an acylation catalyst
Okamoto, Sentaro,Sakai, Yuzo,Watanabe, Saki,Nishi, Shohei,Yoneyama, Aya,Katsumata, Hitomi,Kosaki, Yu,Sato, Rumi,Shiratori, Megumi,Shibuno, Misuzu,Shishido, Tsukasa
, p. 1909 - 1912 (2014/03/21)
Cyclic isothioureas 1, 2, 3, and 4 were synthesized through a four-step procedure from the corresponding ortho-bromoanilines 10 via Pd- or Cu-catalyzed cyclization-benzothiazole formation. Nonbenzo analogues 7, 8, and 9 were synthesized by a condensation reaction of cyclic thioureas 15 and α-bromoacetophenones 14. Investigations of the acylation reactions of 1-phenylethanol with acid anhydrides in the presence of these cyclic isothiourea catalysts revealed their structure-activity relationships. Remarkable electronic effects resulting from substituent(s) on a benzo or phenyl moiety and the influence of the size of the annulating ring were observed. Introduction of an electron-donating substituent(s) enhanced the reaction rate. A few substitution effects on chiral catalysts of type 3 and 7 were also studied.
Synthesis of α-phenyl-1-(R)-(-)-piperidineacetic esters
Juarez, Jorge,Gnecco, Dino,Galindo, Alberto,Enriquez, Raul G.,Marazano, Christian,Reynolds, William F.
, p. 203 - 206 (2007/10/03)
Several α-phenyl-1-(R)-(-)-piperidineacetic esters 3(a-e), were obtained in pure enantiomeric form by condensing (R)-(-)-α-phenylglycine esters 2(a-e) with 1,5-dibromopentane. Similarly, (R)-(-)-α-phenylglycine esters, 2(a-e), were prepared from (R)-(-)-α-phenylglycine 1 with high yields.
