Sonication‐induced gelation : Adaptive gels that are responsive to ultrasound were prepared and characterized. The self‐assembly of the gelators can be controlled by ultrasound (S‐gel) stimuli and renewed by a thermodynamic process (T‐gel, see images).
Double or nothing : The title reaction converts a range of aromatic aldehydes and allenylmethyl/allyl silanes into 1,6‐dioxecane derivatives in good to excellent yields (see scheme; Ar=aryl, Tf=triflate, THF=tetrahydrofuran, TMS=trimethylsilyl). In addition, the bisdiene product has been transformed into the corresponding tricyclic compound through a Diels–Alder reaction.
Continuous organocatalysis : Fast aldol and Mannich reactions require less catalyst when conducted in a microreactor. A proline tetrazole derivative (5–10 mol %) catalyzes asymmetric aldol reactions between various aromatic aldehydes and ketones in microreactor at 60 °C with reaction times ranging from 10 to 30 min.
Secondary, but second to none : The use of secondary alkyl halides in transition‐metal‐catalyzed cross‐coupling reactions (see scheme) has advanced significantly over the last five years. Selected examples of these transformations are examined, including mechanistic and stereochemical aspects.
From blue to red: While four π‐conjugated nitrophenolates absorb within a relatively narrow region in solution, they cover the entire visible spectrum when isolated in vacuo (see picture). The work combines gas‐ and solution‐phase spectroscopy and provides the first benchmark of theoretical excitation energies for nitrophenolates.
