1. Fluorinated Tetraphosphonate Cavitands
Alessandro Pedrini, Federico Bertani, Enrico Dalcanale Molecules. 2018 Oct 17;23(10):2670. doi: 10.3390/molecules23102670.
Two synthetic protocols for the introduction of fluorine atoms into resorcinarene-based cavitands, at the lower and upper rim, respectively, are reported. Cavitand 1, bearing four fluorocarbon tails, and cavitand 2, which presents a fluorine atom on the para position of a diester phosphonate phenyl substituent, were synthesized and their complexation abilities toward the model guest sarcosine methyl ester hydrochloride were evaluated via NMR titration experiments. The effect of complexation on the 19F NMR resonance of the probe is evident only in the case of cavitand 2, where the inset of the cation-dipole and H-bonding interactions between the P=O bridges and the guest is reflected in a sizable downfield shift of the fluorine probe.
2. Asymmetric Total Synthesis of Griseofamine B and Its Three Stereoisomers
Tao Sheng, Caiyun Ma, Guangyan Zhang, Xuan Pan, Zhanzhu Liu J Nat Prod. 2022 Apr 22;85(4):1128-1133. doi: 10.1021/acs.jnatprod.2c00069. Epub 2022 Mar 3.
The first total synthesis of griseofamine B is described starting from l-4-bromo tryptophan methyl ester hydrochloride via five steps and in 18% overall yield. Its three stereoisomers were also synthesized following the same procedure with the yields of 5%, 19%, and 5%, respectively. In vitro antibacterial activities were also evaluated. All four compounds exhibited less potent activity than griseofamine A.
