A highly efficient precatalytic system (XPhos-PdG2) for the Suzuki–Miyaura cross-coupling of 7-chloro-1H-pyrrolo[2,3-c]pyridine employing low catalyst loading

The Application of Microwaves, Ultrasounds, and Their Combination in the Synthesis of Nitrogen-Containing Bicyclic Heterocycles

“…The reactions were performed by using cyclic imines such as 3,4-dihydroisoquinoline; 6,7dihydrothieno[3,2-c]pyridine; 3,4-dihydro-β-carboline; 4,5-dihydro-3H-benz[c]azepine and azaindoles in different conditions of reaction times and temperatures to afford, respectively, the compounds 74a-74d, 75a-75d, 76a-76d, and 77a-77d (Scheme 60). New 7-(hetero)aryl-1H-pyrrolo[2,3-c]pyridine derivatives (78a-p) were synthesized by Savitha et al [117] via the microwave-assisted Suzuki-Miyaura cross-coupling of 7 chloro 6-azaindole and a variety of boronic acid or potassium organotrifluoroborate. The reactions were accomplished with XPhos-PdG2 as a catalyst and potassium phosphate K3PO4 as a base in DMF/EtOH/H2O under microwave heating at 100 °C for 30 min (Scheme 61).…”

“…The 7-azaindoles, 4-azaindoles, and 6-azaindoles exhibited similar reactivities; however, when attempting the reaction with 5-azaindole, it was necessary to employ a catalyst of 10 mol% p-TSA. This higher catalyst amount was required due to the lower reactivity of 5-azaindole, which can be attributed to its higher pKa value (8.42) in comparison to the 6-azaindole (5.61), 4-azaindole (4.85), and 7-azaindole (3.67) New 7-(hetero)aryl-1H-pyrrolo[2,3-c]pyridine derivatives (78a-p) were synthesized by Savitha et al [117] via the microwave-assisted Suzuki-Miyaura cross-coupling of 7-chloro 6-azaindole and a variety of boronic acid or potassium organotrifluoroborate. The reactions were accomplished with XPhos-PdG2 as a catalyst and potassium phosphate K 3 PO 4 as a base in DMF/EtOH/H 2 O under microwave heating at 100 • C for 30 min (Scheme 61).…”

“…The use of MW allowed for reducing the reaction time, avoiding the protodeboronation of boronic acid and improving the yields. New 7-(hetero)aryl-1H-pyrrolo[2,3-c]pyridine derivatives (78a-p) were synthesized by Savitha et al [117] via the microwave-assisted Suzuki-Miyaura cross-coupling of 7 chloro 6-azaindole and a variety of boronic acid or potassium organotrifluoroborate. The reactions were accomplished with XPhos-PdG2 as a catalyst and potassium phosphate K3PO4 as a base in DMF/EtOH/H2O under microwave heating at 100 °C for 30 min (Scheme 61).…”

Application of Palladium Based Precatalytic Systems in the Suzuki‐Miyaura Cross‐Coupling Reactions of Chloro‐ Heterocycles

“…Recently, we have developed an expedient catalytic method for the synthesis of diverse 7-(hetero)aryl-1H-pyrrolo [2,3-c]pyridine analogues via microwave assisted Suzuki-Maura cross-coupling reaction with excellent yield which is compatible with various boronic acids and potassium organotrifluoroborates by employing XPhos Pd G2 precatalyst containing a bulky monodentate biaryl ligand which allows the rapid reductive elimination to form the true mono ligated Pd(0) catalytic species and thereby facilitating the reaction with excellent conversions using low catalyst loadings. Electron deficient boronic acid and polyfluroboronic acids also resulted in good product conversion with very negligible protodeboronation whereas their corresponding BF 3 K salt resulted in excellent conversions [110] (Scheme 20).…”