The distance teaching of organic chemistry to first-year undergraduate students during lockdown represents a challenge for both students and teachers. To face this challenge, a method combining synchronous and asynchronous teaching was presented in this paper. The asynchronous part of the teaching was achieved through the broadcast of videos on the social network Facebook in order to allow each student to progress at his or her own pace. The synchronous part of the teaching was carried out thanks to the Discord platform in order to answer students' questions live (written and oral) as well as to keep a social link with them. The videos have been recorded at home with the minimum of material and the equipment is reported. To assess the efficiency of this alternative teaching compared to distance real-time teaching during disruption, a questionnaire completed by students was used and discussed.

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The selective demethylation of methoxy groups of several multifunctionalized 1,3,5-trimethoxycalix[6]arene-based receptors has been achieved. It is shown in this study that the best reagent is trimethylsilyl iodide (TMSI) and that the conformation adopted by the calixarene core is crucial for both the selectivity and the efficiency of the process. A key feature appears to be the "in" or "out" orientation of the methoxy substituents relative to the macrocyclic cavity. If projected inward, the reaction is slow and not selective. If projected outward, the reaction is fast and selective. A strategy that consists of exploiting the host-guest properties of the receptors to change their conformation and to permit their selective demethylation has been developed. Four cases of such a supramolecular assistance are reported, demonstrating the efficiency of the strategy. Such an allosteric control is highly reminiscent of biological processes allowing selective transformation of multifunctional molecules.