Silicon-rhodamine isothiocyanate for fluorescent labelling

A general approach to S-rhodamines from diaryl thioethers and their application in constructing pH probes

A general strategy for the efficient preparation of S-rhodamines from the condensation of diaryl thioether and 2-carboxybenzaldehydes was reported. We further took a morpholine containing spirolactam structure as an example to illustrate that these S-rhodamine dyes could be utilized to construct fluorescent probes based on the ring-opening process. This work provided a general approach for the synthesis of novel S-rhodamine dyes, thus possibly facilitating the development of fluorescence imaging.

Preparation of Polyfunctionalized Aromatic Nitriles from Aryl Oxazolines

A selective ortho,ortho’‐functionalization of readily available aryl oxazolines by two successive magnesiations with sBu₂Mg in toluene followed by trapping reactions with electrophiles, such as (hetero)aryl iodides or bromides, iodine, tosyl cyanide, ethyl cyanoformate or allylic bromides (39 examples, 62–99 % yield) is reported. Treatment of these aryl oxazolines with excess oxalyl chloride and catalytic amounts of DMF (50 °C, 4 h) provided the corresponding nitriles (36 examples, 73–99 % yield). Conversions of these nitriles to valuable heterocycles are reported, and a tentative mechanism is proposed.

Total Synthesis and Bioactivity Mapping of Geodiamolide H

The first total synthesis of the actin-stabilizing marine natural product geodiamolide H was achieved. Solid-phase based peptide assembly paired with scalable stereoselective syntheses of polyketide building blocks and an optimized esterification set the stage for investigating the key ring-closing metathesis. Geodiamolide H and synthetic analogues were characterized for their toxicity and for antiproliferative effects in cellulo, by characterising actin polymerization induction in vitro, and by docking on the F-actin target and property computation in silico, for a better understanding of structure-activity relationships (SAR). A non-natural analogue of geodiamolide H was discovered to be most potent in the series, suggesting significant potential for tool compound design.