Cyclic thioureaderivatives having three different types of cyclophane structure, ortho-meta, meta-meta, and meta-para, and a lariat-type thiourea, were synthesized, and their anion-binding ability was examined. The association constants for the complexation between the receptors and several anions in DMSO-d(6) were measured by the titration method using (1)H NMR spectroscopy. All receptors, except
Simple cyclophanes containing four distant amino N atoms or ether O atoms behave as hosts for the threading of guest diarylguanidinium ions. The recognition system exhibits high synthetic flexibility, allowing unique O-free [2]rotaxanes to be synthesized efficiently (yields of up to 80%) through both “threading-followed-by-stoppering” and “clipping” approaches.
Modified Julia–Kocienski Reagents for a Stereoselective Introduction of Trisubstituted Double Bonds: A Formal Total Synthesis of Limazepine E and Barmumycin
作者:Guna Sakaine、Gints Smits
DOI:10.1021/acs.joc.8b00643
日期:2018.5.4
A formal total synthesis of pyrrolo[1,4]benzodiazepine anticancer antibiotic family member limazepine E is described. The synthesis features a stereoselective introduction of a trisubstituted double bond using novel sterically demanding Julia–Kocienski reagents, allowing the number of linear steps to be significantly reduced. The potential of the newly developed reagents has also been demonstrated
The present invention discloses compounds of Formula I:
wherein the variables in Formula I are defined as described herein. Also disclosed are pharmaceutical compositions containing such compounds and methods for using the compounds of Formula I in the prevention or treatment of HCV infection.
Enantioselective Seleno‐Michael Addition Reactions Catalyzed by a Chiral Bifunctional N‐Heterocyclic Carbene with Noncovalent Activation
作者:En Li、Jiean Chen、Yong Huang
DOI:10.1002/anie.202202040
日期:2022.6.7
A highly enantioselective Michael addition reaction of alkyl selenols to enones is reported. The development of a chiral bifunctional N-heterocycliccarbene (NHC)/thiourea catalyst was key in obtaining the chiral β-seleno ketones with remarkable selectivity.