THE TELESCOPIC APPROACH AS A TOOL FOR GREEN CHEMISTRY. One-pot reactions have become a powerful tool for the development of sustainable protocols in organic synthesis. In particular, the telescoping of multi-step reactions, i.e., the execution of sequential reactions without isolating and purifying intermediates, reduces the number of steps while preventing waste generation. Additionally, the processes become more sustainable through time, reagents/solvents, energy and cost savings. Therefore, the aim of this work is to summarize and discuss representative one-pot telescoped strategies involving heterocyclic construction, cross-coupling and continuous-flow reactions.

Foi desenvolvido um método fácil e eficiente para a conversão de alcoóis em brometos de alquila em meio neutro, utilizando ácido tribromoisocianúrico e trifenilfosfina (razão molar 1,0:0,7:2,0, álcool/ácido tribromoisocianúrico/trifenilfosfina) em diclorometano à temperatura ambiente. Esse método pode ser aplicado para a conversão de alcoóis primários, secundários, benzílicos e alílicos, sendo os brometos correspondentes obtidos em 67-82% de rendimento. Alcoóis terciários não são reativos sob estas condições.

An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzylic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions.