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Phenylmethanimine is an aromatic imine with a twofold relevance in chemistry: organic synthesis and astrochemistry. To tackle both aspects, a multidisciplinary strategy has been exploited and a new, easily accessible synthetic approach to generate stable imine-intermediates in the gas phase and in solution has been introduced. The combination of this formation pathway, based on the thermal decomposition of hydrobenzamide, with a state-of-the-art computational characterization of phenylmethanimine laid the foundation for its first laboratory observation by means of rotational electric resonance spectroscopy. Both E and Z isomers have been accurately characterized, thus providing a reliable basis to guide future astronomical observations. A further characterization has been carried out by nuclear magnetic resonance spectroscopy, showing the feasibility of this synthetic approach in solution. The temperature dependence as well as possible mechanisms of the thermolysis process have been examined. © 2020 The Authors. Published by Wiley-VCH GmbH

The combination of a practical and highly enantioselective organocatalytic reaction, which allows the stereoselective introduction of a benzodithiol group, with a fluorination step, gives a new and effective strategy for the stereoselective synthesis of difluorinated building blocks. The benzodithiol group is a versatile and chameleonic group that can be further functionalized before fluorination, giving customized and tailored useful synthetic strategies. As an example of the application of this facile strategy, the effective enantioselective synthesis of difluoroarundic acid is described. All you need is fluor! The combination of a practical and highly enantioselective organocatalytic reaction with a fluorination step provides a new and effective strategy for the stereoselective synthesis of enantioenriched difluorinated building blocks (see scheme).

Hydrogenation of meso-octamethylporphyrinogen (calix[4]pyrrole) with a number of heterogeneous catalysts under different experimental conditions has been investigated. GC-MS analyses of the reaction mixtures showed the formation of one to four products in low to moderate yields: three of them were diastereoisomers of the product derived from half-hydrogenation of the substrate, and displayed alternating pyrrolidine and pyrrole rings, while the fourth was the all-cis saturated product. An acidic medium was necessary to achieve hydrogenation. However, the use of too strongly acidic solvents or additives was detrimental to the stability of the substrate and/or the catalyst.

C2-Symmetrical, enantiopure 2,6-di[1-(1-aziridinyl)alkyl]pyridines (DIAZAPs) were prepared by a high-yielding, three-step sequence starting from 2,6-pyridinedicarbaldehyde and (S)-valinol or (S)-phenylglycinol. The new compounds were tested as ligands in palladium-catalyzed allylation of carbanions in different solvents. Almost quantitative yield and up to 99% enantiomeric excess were obtained in the reactions of the enolates derived from malonate, phenyl- and benzylmalonate dimethyl esters with 1,3-diphenyl-2-propenyl ethyl carbonate. Asymmetric synthesis of 2-(2-pyridyl)aziridines from chiral 2-pyridineimines bearing a stereogenic center at the nitrogen atom was development. The envisioned route involves the addition of chloromethyllithium to the imine derived from 2-pyridinealdehyde and (S)-valinol, protected as O-trimethylsilyl ether. The analogous reaction performed on the imine derived from (S)-valine methyl ester gave the product containing the aziridine ring as well as the α-chloro ketone group coming from the attack of chloromethyllithium to the ester function. Other stereogenic alkyl substituents at nitrogen gave less satisfactory results. Moreover, the aziridination protocol did not work on other aromatic imines, e.g. 3-pyridineimine and benzaldimine, which are not capable of bidentate chelation. The N-substituent could not be removed, but aziridine underwent ring-opening by attack of nitrogen, sulfur, and oxygen nucleophiles. Complete or prevalent regioselectivity was obtained using cerium trichloride heptahydrate as a catalyst. In some cases, the N-substituent could be removed by an oxidative protocol. The addition of organometallic (lithium, magnesium, zinc) reagents to 2-pyrroleimines derived from (S)-valinol and (S)-phenylglycinol gave the N-substituted-1-(2-pyrrolyl)alkylamines with high yields and diastereoselectivities. The (S,S)-diastereomers were useful intermediates for the preparation of enantiopure 1-[1-(2-pyrrolyl)alkyl]aziridines by routine

Hydrogenation of meso-octamethylporphyrinogen (calix[4]pyrrole) with a number of heterogeneous catalysts under different experimental conditions has been investigated. GC-MS analyses of the reaction mixtures showed the formation of one to four products in low to moderate yields: three of them were diastereoisomers of the product derived from half-hydrogenation of the substrate, and displayed alternating pyrrolidine and pyrrole rings, while the fourth was the all-cis saturated product. An acidic medium was necessary to achieve hydrogenation. However, the use of too strongly acidic solvents or additives was detrimental to the stability of the substrate and/or the catalyst.

LoRa 2.4GHz is a new version of the original LoRa modulation adapted to transmit on the 2.4GHz ISM (Industrial, Scientific and Medical) band, an unlicensed band characterized by the cohabitation of multiple technologies, including Wi-Fi standards. In this thesis, after a short introduction to the key features of LoRa modulation, will be presented a C-based software library which has been designed for Genuino Zero to control Semtech SX1280, which represents the first transceiver supporting LoRa 2.4GHz modulation. The second part of the thesis will be focused on the experimental assessment of LoRa 2.4GHz Wi-Fi immunity, conducted by exploiting SX1280 transceivers and a firmware designed for the purpose of the experimentation, based on the software library described above. The aim of the research is to characterize the interference against LoRa 2.4GHz generated by two widespread Wi-Fi standards: IEEE 802.11.b and IEEE 802.11.g. The experiments will principally focus on how this kind of interference affecting LoRa transmissions can be mitigated by varying two of the most important parameters of LoRa modulation: Spreading Factor and Bandwidth. The presentation of the obtained results will be preceded by the description of the testbed employed for the experiments.

LoRa 2.4GHz is a new version of the original LoRa modulation adapted to transmit on the 2.4GHz ISM (Industrial, Scientific and Medical) band, an unlicensed band characterized by the cohabitation of multiple technologies, including Wi-Fi standards. In this thesis, after a short introduction to the key features of LoRa modulation, will be presented a C-based software library which has been designed for Genuino Zero to control Semtech SX1280, which represents the first transceiver supporting LoRa 2.4GHz modulation. The second part of the thesis will be focused on the experimental assessment of LoRa 2.4GHz Wi-Fi immunity, conducted by exploiting SX1280 transceivers and a firmware designed for the purpose of the experimentation, based on the software library described above. The aim of the research is to characterize the interference against LoRa 2.4GHz generated by two widespread Wi-Fi standards: IEEE 802.11.b and IEEE 802.11.g. The experiments will principally focus on how this kind of interference affecting LoRa transmissions can be mitigated by varying two of the most important parameters of LoRa modulation: Spreading Factor and Bandwidth. The presentation of the obtained results will be preceded by the description of the testbed employed for the experiments.