Amphidinolides F and C2: An Odyssey in Total Synthesis.

Amphidinolides F, C, C2, and C3 are marine natural products isolated from dinoflagellates Amphidinium species. They share the same macrolactone core, with the difference between them residing at the side chain level. A predominant feature of these amphidinolides is the presence of two trans-THF rings inside the macrolactone core, which is thought to be built by C-glycosylation with titanium enolate of N-acetyl oxazolinethiones. Thus, the original strategy for their total synthesis was based on the assembly of three main fragments corresponding to C1-C9, C10-C19, and C20-C29 or C20-C34 disconnections. Whereas synthesis of all fragments was successful, the C-glycosylation reaction between C19 and C20 turned out to be an issue. Therefore, a second route was designed. The new disconnection between C17 and C18 was based on a sulfone addition and a desulfonylation sequence. Our convergent strategy allowed the total synthesis of amphidinolide F and enabled a new unifying route toward the synthesis of amphidinolides C, C2, and C3 using a late-stage divergent approach. Although there were unsatisfying yields at some critical steps, our work culminated into the first total synthesis of amphidinolide C2.

Stereoselective Ring-Opening of gem-Difluorocyclopropanes: An Entry to Stereo-defined (E,E)- and (E,Z)-Conjugated Fluorodienes.

The ring-opening of gem-difluorocyclopropyl acetaldehydes producing selectively (E,E)- and (E,Z)-conjugated fluorodienals is described. Two stereo-divergent methods are presented to access both stereoisomers from a common precursor, in high yield and selectivity. The mechanistic aspect of these transformations is discussed.

Stable liquid foams from a new polyfluorinated surfactant.

Liquid foams exhibiting long-term stability are a key-challenge in material design. Based on this perspective, new pyridinium polyfluorinated surfactants were synthesized from simple building blocks enabling unusually stable liquid foams. While the batch-generated foams were used for qualitative foaming evaluation, microfluidics allowed a quantitative insight into the aging effects of monodisperse foams.

Total Synthesis of the Marine Macrolide Amphidinolide F.

A new and efficient convergent approach toward the synthesis of amphidinolide F is described through the assembly of three fragments. The two trans-tetrahydrofurans were built by a diastereoselective C-glycosylation with titanium enolate of bulky N-acetyloxazolidinethiones. The side chain was inserted by a Liebeskind-Srogl cross-coupling reaction. A sulfone condensation/desulfonylation sequence, a Stille cross-coupling, and a macrolactonization were applied to connect the fragments.

Synthesis of new hydrophilic rhodamine based enzymatic substrates compatible with droplet-based microfluidic assays.

Here we report the conception, synthesis and evaluation of new hydrophilic rhodamine-based enzymatic substrates for detection of peptidase activity compatible with high-throughput screening using droplet-based microfluidics.