A summary of fluorescent probes for imaging biological pH variations is provided.

Significant progress has been accomplished in directed C–H functionalization through the use of earth-abundant and inexpensive first-row transition metals. Among these base metals, Co is especially attractive in view of its versatile applications in C–H functionalization, in both low- and high-valent states. In this vein, catalytic Co(III) species can be generated from the dissociation of a Cp*Co(III) catalyst or through the oxidation of a low-valent cobalt catalyst in the presence of an oxidant. In this feature article, we will discuss the breakthroughs in Cp*Co(III)-promoted C–H functionalization. In this field, C(sp²)–H functionalization has been extensively studied and developed. In contrast, few C(sp³)–H functionalization reactions have been reported.

It was first observed that PPL, lipase from porcine pancreas, and several other lipases have a promiscuous ability to catalyse asymmetric aldol reactions between acetones and aldehydes in the presence of water.

A coumarin TCF-based water-soluble near-infrared fluorescent probe was presented, which could be used for the rapid, colorimetric and ratiometric detection of SO₂ derivatives with a detection limit of 0.27 nM. Moreover, this probe could successfully image the analyte in living cells.

A novel lipase-catalysed direct Mannich reaction has been developed under aqueous conditions in a “one-pot” strategy. Interestingly, these promiscuous reactions can be greatly promoted by water and generally require aromatic aldehydes.