Natural deep eutectic solvents in the hetero-Diels–Alder approach to bis(indolyl)methanes
作者:Carla Grosso、Amadeu Brigas、Jesús M. de los Santos、Francisco Palacios、Américo Lemos、Teresa M. V. D. Pinho e Melo
DOI:10.1007/s00706-019-02421-7
日期:2019.7
For the first time, the use of natural deepeutecticsolvents (NADES) as reaction media to carry out hetero-Diels–Alder reactions is disclosed. This allowed to improve the efficiency and sustainability of the synthetic approach to bis(indolyl)methanes (BIMs) based on bis-hetero-Diels–Alder/conjugate addition reactions of nitroso- and azoalkenes with indoles. The ternary mixture of H2O with choline
Reactivity of Dipyrromethanes towards Azoalkenes: Synthesis of Functionalized Dipyrromethanes, Calix[4]pyrroles, and Bilanes
作者:Susana M. M. Lopes、Américo Lemos、Teresa M. V. D. Pinho e Melo
DOI:10.1002/ejoc.201402944
日期:2014.11
chains at the 1- and 9-positions of dipyrromethanes was explored by using the hetero-Diels–Alder reaction of azoalkenes. New 5,5′-diethyldipyrromethanes and 5-phenyldipyrromethanes that were functionalized with open-chain hydrazone moieties, including derivatives with tetrazolyl groups, were prepared. Furthermore, the synthesis of new calix[4]pyrroles and bilanes was achieved by employing the bis(hetero-Diels–Alder)
On-Water Synthesis of Dipyrromethanes via Bis-Hetero-Diels–Alder Reaction of Azo- and Nitrosoalkenes with Pyrrole
作者:Américo Lemos、Teresa Pinho e Melo、Nelson Pereira、Susana Lopes
DOI:10.1055/s-0033-1340300
日期:——
An unprecedented one-pot approach to 5-substituted dipyrromethanes based on the hetero-Diels-Alder reaction of azo- and nitrosoalkenes is described. The on-water reaction conditions led to the target compounds in higher yields with significantly shorter reaction times and simpler purification procedures than carrying out the reaction in dichloromethane or in the absence of solvent.