(S)-(1-Pyrrolidin-2-ylmethyl)quinuclidin-1-ium Bromide

(S)-(1-Pyrrolidin-2-ylmethyl)quinuclidine-1-ium bromide was synthesized in a six-step reaction process starting from l-proline and spectroscopically and thermally characterized.This research was funded by the Generalitat Valenciana (Project AICO 2021/013), the Spanish Ministerio de Ciencia, Innovación y Universidades (MICINN, Projects PGC2018-096616-B−I00 and PID2021-127332NB-I00) and the University of Alicante (Projects VIGROB-173 and grant UAUSTI 2021)

Visible light-promoted metal-free aerobic photooxidation of xanthenes, thioxanthenes and dihydroacridines in deep eutectic solvents

Benzylic systems such as 9H-xanthenes, 9H-thioxanthenes and 9,10-dihydroacridines can be easily oxidized to the corresponding xanthones, thioxanthones or acridones, respectively, in deep eutectic solvents by a visible blue light-promoted photooxidation procedure carried out using ambient air as oxidant in the presence of riboflavin tetraacetate as a metal-free photocatalyst. The obtained yields are high or almost quantitative, and the reaction media can be recovered and reused. The environmental friendliness of the protocol is demonstrated based on several green metrics.The authors acknowledge the financial support by the Spanish Ministerio de Ciencia e Innovación (PID2021-127332NB-I00), the Generalitat Valenciana (AICO 2021/013) and the University of Alicante (VIGROB-173 and UAUSTI 2022)

Visible-light-mediated decarboxylative (E)-alkenylation of aliphatic carboxylic acids with aryl styryl sulfones under metal-free conditions

The decarboxylative alkenylation of aliphatic carboxylic acids with aryl styryl sulfones is efficiently catalyzed by riboflavin tetraacetate under visible light irradiation at room temperature. This metal-free protocol is cost-efficient, environmentally friendly and provides the corresponding olefins with excellent (E)-diastereocontrol. The methodology can also be used to prepare internal alkynes regioselectively by using alkynyl sulfones as radical acceptors. The suitability as building blocks of the olefins obtained was demonstrated by performing an (E)- to (Z) photoisomerization, an iron-catalyzed allylic substitution of the phenoxy group derived from the 2-phenoxycarboxylic acid substrates, as well as syn-epoxidations, and diastereoselective intramolecular iodoarylations. Based on control experiments and DFT calculations, we proposed a reaction mechanism that accounts for the regio- and diastereo-selectivity observed.This work was financially supported by the Ministerio de Ciencia e Innovación (MICINN; grant no. CTQ2017-88171-P) and Generalitat Valenciana (SEJIGENT/2021/005, granted to I. B.)