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Polylactide (PLA) polymers containing five distinct lengths of fluorinated (from C 3 F 7 to C 13 F 27 ) and non-fluorinated (C 6 H 13 ) end-groups were successfully synthesized by ring-opening polymerization of d,l -lactide. Fluorination was expected to increase the encapsulation efficiency of perfluorohexane (PFH). 150 nm nanocapsules were obtained and 19 F nuclear magnetic resonance revealed that nanocapsules formulated with fluorinated polymers increased by 2-fold the encapsulation efficiency of PFH compared with non-fluorinated derivatives, without any effect of fluorine chain length. Fluorination of the polymers did not induce any specific in vitro cytotoxicity of nanocapsules towards HUVEC and J774.A1 cell lines. The echogenicity of fluorinated-shelled nanocapsules was increased by 3-fold to 40-fold compared to non-fluorinated nanocapsules or nanoparticles devoid of a perfluorohexane core for both conventional and contrast-specific ultrasound imaging modalities. In particular, an enhanced echogenicity and contrast-specific response was observed as the fluorinated chain-length increased, probably due to an increase of density and promotion of bubble nucleation. When submitted to focused ultrasound, both intact and exploded nanocapsules could be observed, also with end-group dependency, indicating that PFH was partly vaporized. These results pave the way to the design of theranostic perfluorohexane nanocapsules co-encapsulating a drug for precision delivery using focused ultrasound. Statement of Significance We have synthesized novel fluorinated polyesters and formulated them into nanocapsules of perfluorohexane as ultrasound contrast agents. This nanosystem has been thoroughly characterized by several techniques and we show that fluorination of the biodegradable polymer favors the encapsulation of perfluorohexane without producing further reduction of cell viability. Contrary to nanocapsules of perfluoroctyl bromide formulated with the fluorinated polymers [32], the presence of the fluorinated moieties leads to an increase of echogenicity that is dependent of the length of the fluorinated moiety. Morevover, the ability of nanocapsules to explode when submitted to focused ultrasound also depends on the length of the fluorinated chain. These results pave the way to theranostic perfluorohexane nanocapsules co-encapsulating a drug for precision delivery using focused ultrasound. [ABSTRACT FROM AUTHOR]

The first enantioselective total syntheses of two marine sesquiterpenes, natural (1S)-suberosanone and (1S)-suberosenol A, are achieved leading to the assignment of the absolute configuration of natural suberosenol A. A new access to (1S)-suberosenone from a key tricyclic enone was also developed leading to an overall improvement of the synthesis, allowing an efficient route to suberosenol A. Hyperbaric asymmetric Michael addition and a highly efficient silver trifluoroacetate mediated α-alkylation for the formation of ring A completed the key steps of the synthesis. Regrettably, synthetic (1S)-suberosanone did not retain the reported picomolar cytotoxic activity displayed by the natural product, the reason for which remains to be elucidated. [ABSTRACT FROM AUTHOR]

Two new series of pyran- or coumarin-substituted thiazolyl-pyrazole-chromen-2-one derivatives 10a-10d and 11a-11d were efficiently synthesized under environmentally friendly reaction conditions through a convenient one-pot multicomponent reaction of a heterocyclic bromoacetyl derivative 3 or 4 with thiosemicarbazide and a substituted 3-(acetoacetyl) coumarin derivative 5a-5d in anhydrous ethanol. The reac-tion proceeds through Hantzsch thiazole and Knorr pyrazole syntheses in refluxing ethanol. The key features of this approach are its operational simplicity, the quick access to the desired products, and the good to excellent yields. The structures of the newly synthesized compounds were established by IR spectroscopy, ¹H, 13C, and 2D NMR spectroscopy, and mass spectrometry. [ABSTRACT FROM AUTHOR]

A controllable method for the functionalization of XantPhos Pd-G3 precatalyst with thiosugars and thiols has been established. Under mild and operationally simple reaction conditions through just mixing of precatalyst and thiosugars (α- or β-mono-, di- and poly-thiosugar derivatives) in water at 25 °C for 20 min, a series of 1-aminobiphenyl thioglycosides that are difficult to synthesize by classical methods has been synthesized in very high yields., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)