Ring-opening reactions of benzotriazoles with Wittig reagents
摘要:
Nonafluorobutanesulfonyl-1H-benzotriazole affords phenylazomethylenetriphenylphosphoranes upon treatment with in situ generated alkyl triphenylphosphoranylidenes. Methylenetriphenylphosphorylidene yields the corresponding bis-phenylazomethylene-triphenylphosphorane. (c) 2006 Elsevier Ltd. All rights reserved.
Reaction of N-Nonaflylbenzotriazole with Silyl Enol Ethers
作者:Thomas Ziegler、Moritz Uhde
DOI:10.1055/s-0028-1083371
日期:2009.4
N-Nonaflylbenzotriazole reacts with trimethylsilyl enol ethers in tetrahydrofuran at room temperature under tetrabutylammonium fluoride catalysis to afford o-(nonafluorobutylsulfonamido)phenylhydrazones in 19-82% yield. N-Nonaflylbenzotriazole reacts twice with the less sterically demanding silyl enol ethers to afford the corresponding o-(nonafluorobutylsulfonamido)phenylazo enols in 41-75% yield.
Facile NN Activation in Benzotriazole: Capturing the Dimroth Azo/Triazole Intermediate by Complexation to Iridium
作者:D. Scott Bohle、Zhijie Chua、Inna Perepichka
DOI:10.1002/cplu.201300245
日期:2013.10
The in situ observation of benzotriazole ring and ring-opened isomers, which result from the Dimroth equilibrium for 1-[(nonafluorobutane)sulfonyl]benzotriazole, 1, in solution by 19 F NMR and UV/Vis spectroscopy is reported. Two benzotriazoles, compound 1 and 1,1'-sulfonylbis(benzotriazole) (3), undergo Dimrothtriazole ring opening and coordination to an iridium(I) metal center to give either linear
据报道,通过19 F NMR和UV / Vis光谱对溶液中1-[((九氟丁烷)磺酰基]苯并三唑1)的Dimroth平衡进行了原位观察,结果表明苯并三唑环和开环异构体。化合物1和1,1'-磺酰基双(苯并三唑)(3)的两个苯并三唑经历Dimroth三唑开环并与铱(I)金属中心配位,得到任一线性重氮[IrI(η1-NNPhNSO2C4 F9)(Cl )(PPh3)2](2)或不寻常的双弯曲重氮[IrIII(η3-NNPhNSO2Btz)(Cl)(PPh3)2](4; Btz =苯并三唑)络合物。
A Resourceful Access to α-Functionalized Arylhydrazones
作者:Thomas Ziegler、Lakshminarayanapuram R. Subramanian、Muhammad Usman Anwar、Sonja Tragl
DOI:10.1055/s-2006-926247
日期:——
Several compounds containing active methylene groups flanked by carbonyl, cyano or nitro groups were reacted with N-nonaflylbenzotriazole (BtNf, 1) at room temperature. An instantaneous reaction took place, which was complete within 10-30 minutes. All active methylene compounds gave hydrazono derivatives by the attack of the carbon nucleophile at the nitrogen in position 2 of the BtNf followed by ring-opening, thus providing a new access to α-functionalized arylhydrozones.
N-Nonaflyl-benzotriazole 1a reacts with enamines 2 in tetrahydrofurane (THF) at room temperature to afford o-nonafluorobutansulfonamido-phenylazo-enamines 3 in 74-81% yield. Compound 1a reacts with 1-diethylaminobutadien 2f twice, affording pyridazine derivative 3f in 20% yield. Ringopening of N-cyano-benzotriazole 1b with pyrrolidinocyclohexene 2a affords, under cleavage of pyrrolidine 1,2,3,4-tetrahydro-dibenzo[4,5:e]imidazo[1,2-b][1,2,4]triazine 4 in 43% yield.