- Synthesis of polystyrene-supported Pd(II)-containing macrocyclic complex as a reusable catalyst for chemoselective Suzuki–Miyaura coupling reaction
-
A polystyrene-supported Pd complex bearing a cyclic pyridine-2,6-bisiamide ligand was synthesized and its catalytic activity in the Suzuki–Miyaura coupling reaction of 2,6-bromopyridine with 4-methoxyphenylboronic acid in aqueous media was investigated. The solid-supported catalyst exhibited catalytic activity and chemoselectivity that were comparable to those of homogeneous catalyst. The reusability of the solid-supported catalyst was also examined.
- Yamamoto, Koji,Nameki, Riku,Sogawa, Hiromitsu,Takata, Toshikazu
-
supporting information
(2020/04/02)
-
- Selective palladium-catalysed arylation of 2,6-dibromopyridine using N-heterocyclic carbene ligands
-
A selective palladium-catalysed arylation of 2,6-dibromopyridine has been developed by employing N-heterocyclic carbene ligands. Selective mono-arylation was performed in water/acetonitrile solvent system at ambient temperature with catalyst loading of 0.1 mol%. This reaction was also found to proceed smoothly in water although at a slightly elevated temperature of 80 °C. 2,6-Disubstituted and diversely substituted 2,6-pyridines were also obtained in high yields which will be of importance to organic and medicinal chemists.
- Prajapati,Schulzke,Kindermann,Kapdi
-
p. 53073 - 53085
(2015/06/25)
-
- Design, synthesis, and biological evaluation of novel pyridine-bridged analogues of combretastatin-A4 as anticancer agents
-
A series of novel pyridine-bridged analogues of combretastatin-A4 (CA-4) were designed and synthesized. As expected, the 4-atom linker configuration retained little cytotoxicities in the compounds 2e, 3e, 3g, and 4i. Activities of the analogues with 3-atom linker varied widely depending on the phenyl ring substitutions, and the 3-atom linker containing nitrogen represents the more favorable linker structure. Among them, three analogues (4h, 4s, and 4t) potently inhibited cell survival and growth, arrested cell cycle, and blocked angiogenesis and vasculature formation in vivo in ways comparable to CA-4. The superposition of 4h and 4s in the colchicine-binding pocket of tubulin shows the binding posture of CA-4, 4h, and 4s are similar, as confirmed by the competitive binding assay where the ability of the ligands to replace tubulin-bound colchicine was measured. The binding data are consistent with the observed biological activities in antiproliferation and suppression of angiogenesis but are not predictive of their antitubulin polymerization activities.
- Zheng, Shilong,Zhong, Qiu,Mottamal, Madhusoodanan,Zhang, Qiang,Zhang, Changde,Lemelle, Elise,McFerrin, Harris,Wang, Guangdi
-
p. 3369 - 3381
(2014/05/20)
-
- An efficient approach to mechanically planar chiral rotaxanes
-
We describe the first method for production of mechanically planar chiral rotaxanes in excellent enantiopurity without the use of chiral separation techniques and, for the first time, unambiguously assign the absolute stereochemistry of the products. This proof-of-concept study, which employs a chiral pool sugar as the source of asymmetry and a high-yielding active template reaction for mechanical bond formation, finally opens the door to detailed investigation of these challenging targets.
- Bordoli, Robert J.,Goldup, Stephen M.
-
supporting information
p. 4817 - 4820
(2014/04/17)
-
- Palladium-catalyzed highly regioselective 2-arylation of 2,x-dibromopyridines and its application in the efficient synthesis of a 17β-HSD1 inhibitor
-
2,3- and 2,5-Dibromopyridines reacted with arylboronic acids, catalyzed by Pd(OAc)2/PPh3 in the presence of K2CO 3 in CH3CN/MeOH (2:1) at 50 C for 24 h, to afford 2-arylpyridines in good to high yield
- Zhou, Qizhong,Zhang, Bin,Su, Liangjun,Jiang, Tiansheng,Chen, Rener,Du, Tieqi,Ye, Yuyuan,Shen, Jianfen,Dai, Guoliang,Han, Deman,Jiang, Huajiang
-
p. 10996 - 11003
(2014/01/06)
-
- Inhibiting copper(i) iodide aggregate assembly in the solid state via macrocyclic encapsulation
-
Three CuI complexes of diimine-bearing macrocyclic ligands are described. Reaction of CuI with macrocycles of different ring size gives rise to differing degrees of aggregation of (CuI)n in the solid state. X-Ray diffraction studies reveal that
- Smith, David J.,Blake, Alexander J.,Wilson, Claire,Champness, Neil R.
-
experimental part
p. 12257 - 12264
(2012/01/31)
-
- Synthesis of novel halopyridinylboronic acids and esters. Part 4: Halopyridin-2-yl-boronic acids and esters are stable, crystalline partners for classical Suzuki cross-coupling
-
This paper describes some methods for the synthesis and the isolation of novel 5 or 6-halopyridin-2-yl-boronic acids and esters 3, 4, 7. These compounds are prepared via a regioselective halogen-metal exchange using n-butyllithium and subsequent quenching with triisopropylborate starting from appropriate dihalopyridines. All substrates studied to date provided a single regioisomeric boronic acid or ester product. Additionally, these compounds have been found to undergo Pd-catalysed coupling with arylhalides and authorise a strategy to produce new pyridines libraries.
- Bouillon, Alexandre,Lancelot, Jean-Charles,Santos, Jana Sopkova De Oliveira,Collot, Valérie,Bovy, Philipppe R.,Rault, Sylvain
-
p. 10043 - 10049
(2007/10/03)
-
- Synthesis of oligopyridines and their metal complexes as precursors to topological stereoisomers
-
(Matrix Presented) Palladium-based carbon-carbon coupling reactions in sequence with halogen-exchange chemistry on a series of heterocycles lead to an effecient synthetic strategy for oligopyridines that bind metal ions such as ruthenium to form coordinat
- Benaglia, Maurizio,Ponzini, Francesco,Woods, Craig R.,Siegel, Jay S.
-
p. 967 - 969
(2007/10/03)
-
- Trinuclear copper(I)-bipyridine triskelion: Template/bascule control of coordination complex stereochemistry in a trefoil knot precursor
-
The construction of molecules such as knots and links can be facilitated by using metal-ligand coordination complexes as template structures; however, the control of the stereochemistry by cooperative steric interactions among metal-ligand sites remains a challenge. A simple, but general, cantilever control mechanism is demonstrated here through the stereoselective synthesis of a trinuclear copper(I)-bipyridine triskelion (see picture).
- Woods, Craig R.,Benaglia, Maurizio,Toyota, Shinji,Hardcastle, Kenneth,Siegel, Jay S.
-
p. 749 - 751
(2007/10/03)
-