Preparation of zinc organometallics derived from nucleosides and nucleic acid bases and Pd(0) catalyzed coupling with aryl iodides

Triflimide-Promoted Nucleophilic <i>C</i>-Arylation of Halopurines to Access <i>N</i>⁷-Substituted Purine Biaryls

“…General Melting points were measured using a Büchi B 545 apparatus and are uncorrected. 1 H-and 13 C-NMR spectra were recorded with a JEOL JMN-400 spectrometer operating at 400 and 100 MHz in CDCl 3 at 25 °C with tetramethylsilane (δ = 0 ppm) as the internal standard. The data are reported as follows: chemical shift in ppm (δ), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, br s = broad singlet, m = multiplet), coupling constant (Hz), and integration.…”

“…11) However, the versatility of this method has not yet been extensively studied; thus, there is progress to be made regarding the potential substrate scope on the synthesis of purine biaryl compounds. Recently, transition metal-catalyzed Suzuki, Stille, Kumada, and Negishi coupling reactions making use of boron, tin, magnesium, or zinc-functionalized aromatic compounds have been proposed as versatile methods for synthesizing N 9 -substituted purine biaryl from 6-halopurine constituents [12][13][14][15][16][17][18][19] (Chart 1). An alternative coupling strategy has also been reported; it utilized stoichiometric quantities of aluminum chloride (AlCl 3 ) as a Lewis acid to induce a reaction between halopurines and aromatic nucleophiles.…”

Transmetalation Reactions Producing Organocopper Reagents

“…Insertion of zinc dust into aryl or heteroaryl iodides is also possible, but polar cosolvents are required in some cases [48,49]. The use of highly activated zinc (Rieke zinc) prepared by reduction of zinc halides with lithium results in faster insertion (Scheme 2.24) [50][51][52].…”

Tri-2-furylphosphine

“…53 The cross-coupling of organoboron derivatives (Suzuki reaction) 54 has also been carried out with TFP as ligand, with apparent benefit. 53 The cross-coupling of organoboron derivatives (Suzuki reaction) 54 has also been carried out with TFP as ligand, with apparent benefit.…”