Monodentate phosphines provide highly active catalysts for Pd-catalyzed C-N bond-forming reactions of heteroaromatic halides/amines and (H)N-heterocycles was written by Anderson, Kevin W.;Tundel, Rachel E.;Ikawa, Takashi;Altman, Ryan A.;Buchwald, Stephen L.. And the article was included in Angewandte Chemie, International Edition in 2006.Related Products of 3528-58-3 This article mentions the following:
Highly reactive catalysts based on palladium and dialkylbiarylphosphino ligands provide unprecedented reactivity and selectivity in C-N bond-forming processes. The bulky monophosphine catalyst system Pd2(dba)3/I is effective for the reaction of aryl/heteroaryl halides bearing primary amides and 2-aminoheterocycles, thus showing that monodentate phosphines are viable alternatives to, and sometimes superior to, chelating ligands. E.g., amination of 3-chlorobenzamide by morpholine gave 81% II. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3Related Products of 3528-58-3).
1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 °C).Pyrazole used as a ligand to prepare organometallic compounds. The presence of both electronegative nitrogen atoms in the pyrazole ring reduces the electron density of the C3- and C5-positions leaving electron density of C4-position unaltered. Thus the C4-position is vulnerable to electrophilic attack. The C3 electrophilic-position may undergo deprotonation in the presence of a strong base leading to ring opening.Related Products of 3528-58-3
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics