1580490-75-0Relevant academic research and scientific papers
Dramatic Acceleration of an Acyl Transfer-Initiated Cascade by Using Electron-Rich Amidine-Based Catalysts
Ahlemeyer, Nicholas A.,Streff, Emma V.,Muthupandi, Pandi,Birman, Vladimir B.
, p. 6486 - 6489 (2017/12/26)
A tandem rearrangement of α,β-unsaturated thioesters into tricyclic ene-lactones fails with conventional amidine-based catalysts, but becomes possible when their electron-rich analogs are employed. A highly diastereo- and enantioselective version of this process has been developed using H-PIP 1b, a chiral catalyst prepared over a decade ago, but never utilized since its disclosure.
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.
