Copper-Mediated Synthesis of Substituted 2-Aryl-N-benzylbenzimidazoles and 2-Arylbenzoxazoles via C–H Functionalization/C–N/C–O Bond Formation
摘要:
An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime ethers to functionalized 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles is described. The protocol involves a copper(II)-mediated cascade C-H functionalization/C-N/C-O bond formation under neutral conditions. Substrates having either electron-donating or -withdrawing substituents undergo the cyclization to afford the target heterocycles at moderate temperature.
The use of enaminones and enamines as effective synthons for MSA-catalyzed regioselective synthesis of 1,3,4-tri- and 1,3,4,5-tetrasubstituted pyrazoles
In the present work, an efficient regioselectivesynthesis of 1,3,4-tri- and 1,3,4,5-tetrasubstituted pyrazoles via a methanesulfonic acid (MSA)-catalyzed reaction of hydrazones with enaminones or enamines is reported. Mechanistically, the formation of the title compounds involves the [2+3] cycloaddition of hydrazones with enaminones or enamines followed by aromatization with acid and oxygen. This
An efficient gold-catalyzedcyclization/arylidene group transfer cascade reaction of N-propioloyl hydrazones has been developed. This method provides a novel approach for the synthesis of various functionalized 4-arylidenepyrazolones.
cycloaddition of nitrile imines with 3-alkenyl-oxindoles was catalyzed by a new chiral Mg(ClO4)2 complex of an N,N′-dioxide ligand. The reaction is so far the sole catalytic synthesis of spiro-pyrazoline-oxindole derivatives. A wide variety of substrates were explored to obtain good yields (up to 98%) and excellent enantioselectivities (up to 99%). This cycloaddition expands the scope of propargyl anion type 1
New Types of Base-Stabilized Alkyl Aluminum, Gallium, and Indium Complexes
作者:Sung-Joon Kim、Namkeun Yang、Dae-Hyun Kim、Sang Ook Kang、Jaejung Ko
DOI:10.1021/om000285o
日期:2000.10.1
Novel dinuclear metalcomplexes with the general formula [(Me2M)NC5H4 C(R)NNC6H5}(MMe3)] (M = Al, R = CH3 (1); M = Ga, R = CH3 (2); M = Al, R = H (3); M = Ga, R = H (4)) result when 2-pyridinecarboxaldehyde phenyl hydrazone ligands are mixed with trimethylaluminum and -gallium. The decagallium complex (GaMe2)8(GaMe)2(μ4-O)2(μ3-O)4(C12H10N3)2 (5) was isolated during the synthesis of 4 as a minor orange
具有通式[(Me 2 M)NC 5 H 4 C(R)NNC 6 H 5 }(MMe 3)]的新型双核金属配合物(M = Al,R = CH 3(1); M = Ga, R = CH 3(2); M = Al,R = H(3); M = Ga,R = H(4))是将2-吡啶羧醛苯基配体与三甲基铝和-镓混合而成的结果。所述decagallium络合物(游戏2)8(游戏)2(μ 4 -O)2(μ 3 -O)4(C 12在合成作为次要橙色产物的4的过程中分离出H 10 N 3)2(5)。合成了三种通式[(Me 2 M)(SC 4 H 3 CHNNC 6 H 5)] 2(M = Al(6); M = Ga(7); M = In(8))的双核金属化合物通过噻吩甲醛甲醛苯hydr与三甲基铝,-镓和-铟的甲烷消除反应。该μ 4 -氧代配合物[(ME 2)个2(OC 4 H ^通过呋喃甲醛苯hydr与三甲基铟的反应制备3
Nitrofuran drugs beyond redox cycling: Evidence of Nitroreduction-independent cytotoxicity mechanism
ROS exhibited the highest cell toxicity among all derivatives. Inhibition of cytosolic glutathione-S-transferase activity by some derivatives was also observed. Finally, only nitrofuranderivatives displayed antibacterial effect. Results suggest that the combined 2-hydrazonylfuran moiety, redox cycling of 5-nitrofuran, and inhibitory effects on antioxidant enzymes, would be finally responsible for the