The 11C-monomethylstannate prepared from [11C]-methyl iodide and Lappert's stannylene, was subject to a palladium-mediated cross-coupling reaction with an aryl halide under ligand-free conditions, to afford easily purified 11C-methyl(hetero)arenes in high radiochemical yields.
Homoleptic lithium tri‐ and tetraalkyl zincates were reacted with a set of bromopyridines. Efficient and chemoselective bromine–metal exchanges were realized at roomtemperature with a substoichiometric amount of nBu4ZnLi2⋅TMEDA reagent (1/3 equiv; TMEDA=N,N,N′,N′‐tetramethylethylenediamine). This reactivity contrasted with that of tBu4ZnLi2⋅TMEDA, which was inefficient below one equivalent. DFT calculations
Deaminative Reductive Cross-Electrophile Couplings of Alkylpyridinium Salts and Aryl Bromides
作者:Jennie Liao、Corey H. Basch、Megan E. Hoerrner、Michael R. Talley、Brian P. Boscoe、Joseph W. Tucker、Michelle R. Garnsey、Mary P. Watson
DOI:10.1021/acs.orglett.9b01014
日期:2019.4.19
A nickel-catalyzed reductive cross-coupling of alkylpyridinium salts and aryl bromides has been developed using Mn as the reductant. Both primary and secondary alkylpyridinium salts can be used, and high functional group and heterocycle tolerance is observed, including for protic groups. Mechanistic studies indicate the formation of an alkyl radical, and controlling its fate was key to the success
Simple Nickel Salts for the Amination of (Hetero)aryl Bromides and Iodides with Lithium Bis(trimethylsilyl)amide
作者:Gabriel Espinosa Martinez、Joseph W. Nugent、Alison R. Fout
DOI:10.1021/acs.organomet.8b00567
日期:2018.9.24
report a protocol in which simple nickel salts catalyze the C–Ncross-couplingreaction between (hetero)arylbromides and iodides with lithium bis(trimethylsilyl)amide without the need for any additive ligand. This method is amenable to low nickel catalyst loadings (1%) as well as gram-scale reactions. Because of the good functional group tolerance and compatibility with heterocyclic moieties, this method
Symmetrical Bisquinolones via Metal-Catalyzed Cross-Coupling and Homocoupling Reactions
作者:Jamshed Hashim、Toma N. Glasnov、Jennifer M. Kremsner、C. Oliver Kappe
DOI:10.1021/jo052283p
日期:2006.2.1
Functionalized 4,4‘-bisquinolones can be efficiently synthesized by microwave-assisted palladium(0)-catalyzed one-pot borylation/Suzukicross-coupling reactions or via nickel(0)-mediated homocouplings of 4-chloroquinolin-2(1H)-one precursors. Both methods are also applicable to other types of symmetrical biaryls.