Pdo.o2Ceo.98O2: a copper- and ligand-free quasi-heterogeneous catalyst for aquacatalytic Sonogashira cross-coupling reaction

The Current Status of Heterogeneous Palladium Catalysed Heck and Suzuki Cross-Coupling Reactions

“…The substitution of foreign metal ions into the lattice of reducible oxides such as CeO 2 and TiO 2 to form ionic solid-solution oxides (Ce 1-x M x O 2-δ or Ti 1-x M x O 2-δ ) has given materials which show high activity for a variety of catalytic reactions, especially in gas-phase oxidation reactions [ 11 , 43 , 44 , 45 , 46 , 47 , 48 ]. However, such catalysts have rarely been applied to C–C cross-coupling reactions [ 49 , 50 , 51 ]. Recently, Burange and co-workers [ 44 ] reported that the ionic ceria-zirconia (CeZrO 4-δ ) solid-solution oxides exhibit high redox properties and thermal stability that make them better catalyst supports than the pure metal oxide counterparts [ 52 ].…”

Copper- and Ligand-Free Sonogashira Cross-Coupling: Access to Novel 3-Aminoindole Derivatives and Their Biological Evaluations

“…To circumvent the formation of the Songashira byproducts, several methods were developed to address this. Such synthetic methods were reported by Soheili et al [28], Mpungose and co-workers [29], Dewan and co-investigators [30], Nikoshvili et al [31], Gholap et al [32], and Lehr and co-workers [33]. We started our investigations with 2-iodoanaline 5 and phenylacetylene 6 as model substrates for the copper-and ligand-free Sonogashira type reaction (Scheme 3).…”

II- from ecological recycling of Pd to greener sonogashira cross-coupling reactions

“…Overall, the reaction required small catalytic amount and was performed under mild conditions in terms of temperature, reaction time and pH. These experimental conditions produced here through the ecocatalysis surpass systems produced by conventional methods by a large margin (Alb eniz and Carrera, 2011;Ayogu and Onoabedje, 2019;Corma et al, 2006;Crudden et al, 2005;Cui et al, 2017;Dantas Ramos et al, 2004;Dioos et al, 2006;Elhampour and Nemati, 2017;Gao et al, 2010;Garg et al, 2005;Khalafi-Nezhad and Panahi, 2011;Li, 2005;Li et al, 2017;Liang et al, 2005;Lohmann et al, 2005;Mori et al, 2008;Mpungose, 2017;Nasrollahzadeh et al, 2014a;Rajender Reddy et al, 2006;Raju et al, 2006;Sadjadi, 2018;Sadjadi et al, 2019;Yi et al, 2012;Khazaei et al, 2013;Nasrollahzadeh et al, 2014b;Sathelly et al, 2016;Nasrollahzadeh et al, 2014c;Thomidis and Exadaktylou, 2008).…”

“…Driven by the need to develop more sustainable procedures, many efforts have been made to develop ligand-free, cocatalystfree, and additive-free conditions, and/or routes using a recyclable Pd catalyst. Although the immobilization of Pd species onto a suitable solid support has been widely studied, leaching remains a problem and recyclability must be improved (Chinchilla and N ájera, 2011;Alb eniz and Carrera, 2011;Ayogu and Onoabedje, 2019;Corma et al, 2006;Crudden et al, 2005;Cui et al, 2017;Dantas Ramos et al, 2004;Dioos et al, 2006;Elhampour and Nemati, 2017;Gao et al, 2010;Garg et al, 2005;Khalafi-Nezhad and Panahi, 2011;Li, 2005;Li et al, 2017;Liang et al, 2005;Lohmann et al, 2005;Mori et al, 2008;Mpungose, 2017;Nasrollahzadeh et al, 2014a;Rajender Reddy et al, 2006;Raju et al, 2006;Sadjadi, 2018;Sadjadi et al, 2019;Yi et al, 2012). Recently, these problems have been addressed using natural systems to synthesize new and active heterogeneous Pd catalysts.…”