210694-00-1Relevant articles and documents
Electronic dependence of C-O reductive elimination from palladium (aryl)neopentoxide complexes
Widenhoefer, Ross A.,Buchwald, Stephen L.
, p. 6504 - 6511 (2007/10/03)
Thermal decomposition of the palladium (aryl)neopentoxide complexes [P-P]Pd(Ar)OCH2CMe3 [P-P =Tol-BINAP or BINAP; Ar p-C6H4CHO (1b), p-C6H4COPh (1c), p-C6H4NO2 (1d), o-C6H4NO2 (1e), o-C6H4CN (1F)] possessing substituents on the palladium-bound aryl group suitable for delocalization of negative charge led to quantitative (≤95%) formation of aryl ether without detectable β-hydride elimination. Thermal decomposition of 1b-f obeyed first-order kinetics, and the rate of reductive elimination decreased in the order o-NO2 > p-NO2 > p-CHO > p-COPh > o-CN. Conversely, thermal decomposition of the related derivatives [P-P]Pd(Ar)OCH2CMe3 [P-P = Tol-BINAP or BINAP; Ar p-C6H4Cl (1g), m-C6H4NO2 (1h), m-C6H4CN (1i)] which did not possess a resonance stabilizing group on the palladium-bound aryl group led to no detectable formation of aryl ether. These and related data point to the buildup of negative charge in the palladium-bound aryl group in the transition state for C-O reductive elimination and are consistent with a mechanism initiated by inner-sphere nucleophilic attack of the alkoxide ligand at the ipso-carbon atom of the palladium-bound aryl group through a zwitterionic Meisenheimer-type intermediate or transition state.
N-Arylpiperazinyl-N'-propylamino derivatives of heteroaryl amides as functional uroselective α1-adrenoceptor antagonists
Elworthy, Todd R.,Ford, Anthony P. D. W.,Bantle, Gary W.,Morgans Jr., David J.,Ozer, Rachel S.,Palmer, Wylie S.,Repke, David B.,Romero, Magarita,Sandoval, Leticia,Sjogren, Eric B.,Talamás, Francisco X.,Vazquez, Alfredo,Wu, Helen,Arredondo, Nicolas F.,Blue Jr., David R.,DeSousa, Andrea,Gross, Lisa M.,Kava, M. Shannon,Lesnick, John D.,Vimont, Rachel L.,Williams, Timothy J.,Zhu, Quan-Ming,Pfister, Jürg R.,Clarke, David E.
, p. 2674 - 2687 (2007/10/03)
Novel arylpiperazines were identified as α1-adrenoceptor (AR) subtype- selective antagonists by functional in vitro screening. 3-[4-(ortho- Substituted phenyl)piperazin-1:yl]propylamines were derivatized with N,N- dimethyl anthranilamides, nicotinamides, as well as carboxamides of quinoline, 1,8-naphthyridine, pyrazolo[3,4-b]pyridine, isoxazolo[3,4- b]pyridine, imidazo[4,5-b]pyridine, and pyrazolo[1,5-a]pyrimidines. Strips of rabbit bladder neck were employed as a predictive assay for antagonism in the human lower tract. Rings of rat aorta were used as a 'negative screen' for the test antagonists. Binding to α1-ARs was relatively sensitive to size and electronic features of the arylpiperazine portion of the antagonists and permissive to these features on the heteroaryl carboxamide side. These structure-affinity findings were exploited to produce nicotinamides (e.g. 13ii and 25x) and pyrazolo[3,4-b]pyridines (e.g. 37f and 37y) ligands with nanomolar affinity at the α1-AR subtype prevalent in the human lower urinary tract (pA2 values: 8.8, 10.7, 9.3, and 9.9, respectively) and displaying 2-3 orders of magnitude selectivity over the α(1D)-AR.