Isatoic anhydride is elaborated to water soluble bioconjugation reagents that gives functionality and water solubility in one self-cleaning step. This new platform offers high atom economy with carbon dioxide being the only byproduct, and is shown to very quickly and efficiently label proteins in bicarbonate buffered solutions.

Why is it π? The first X‐ray crystal structure of a cuprate–carbonyl π‐complex has been obtained for the intermediate prepared from Me2CuLi and fluorenone (see scheme). It is also the first structure of a π‐complex between an organocuprate and a double bond of any kind.

Grow slow: The usual direct treatment of MeLi and CuSPh did not yield X-ray quality crystals of MeCu(SPh)Li. An indirect method starting from Me2CuLi⋅LiSPh and chalcone afforded the desired crystals by the slow reaction of the intermediate π-complex (see scheme). This strategy produced the first X-ray crystal structure of a Posner cuprate. A complementary NMR study showed that the contact ion pair was also the main species in solution.

Asymmetric synthesis of the biologically active xanthone dimer griffipavixanthone (GPX) is reported along with its absolute stereochemistry determination. Synthesis of the natural product is accomplished via dimerization of a p-quinone methide (p-QM) using a chiral phosphoric acid (CPA) catalyst to afford a protected precursor in excellent diastereo-and enantioselectivity. Mechanistic studies, including an unbiased computational investigation of chiral ion-pairs using parallel tempering (PT), were performed in order to probe the mode of asymmetric induction.