聚乙烯吡咯烷酮(PVP–N 2 O 4)上负载的四氧化二氮:一种新的硫醇亚硝化和偶联剂,以及一种硫化物和二硫化物的选择性氧化剂
摘要:
将气态N 2 O 4固定在聚乙烯吡咯烷酮上,得到稳定的聚合试剂。硫醇转化为小号在使用这个新的亚硝化剂-nitrosothiols(thionitrites)ñ -己烷或氯仿3在10℃下。使用该试剂,硫醇也被转化为其相应的二硫化物。在室温下,也可以通过该试剂将硫化物选择性氧化为亚砜,将二硫化物选择性氧化为硫代磺酸盐。通过使用过量的试剂,在室温下也从硫醇选择性地一锅合成硫代磺酸盐。
Abstract Efficient N‐nitrosation of amines, amides, and ureas, and also S‐nitrosation of thiols were performed with dinitrogentetroxide impregnated on activated charcoal (N2O4/charcoal) in CH2Cl2 at room temperature. High selectivity was observed for N‐nitrosation of dialkyl amines, N‐alkylamides and N‐alkylureas. Dealkylation and N‐nitrosation of trialkylamines were also performed by this reagent
Silica-Acetate Complex of N<sub>2</sub>O<sub>4</sub>: A Heterogeneous Reagent for the Selective Nitration of Phenols and Nitrosation of Thiols
作者:N. Iranpoor、H. Firouzabadi、R. Heydari
DOI:10.1081/scc-120016310
日期:2003.1.4
Abstract Complexation of gaseous N2O4 with acylated silica gel affords an addition compound, which is an efficient heterogeneous reagent for the selective mono- and dinitration of phenol, substituted phenols and nitrosation of thiols.
Silica-Polyethyleneglycols/N 2 O 4 Complexes as Heterogeneous Nitrating and Nitrosating Agents
作者:N. Iranpoor、H. Firouzabadi、R. Heydari
DOI:10.1080/10426500307863
日期:2003.5.1
Silica-chloride was reacted with different quantities of H(OCH 2 CH 2 ) n OH (n = 2-4) to furnish silica-based linear polyethylene glycols and cyclic polyethylene glycolic ethers. The N 2 O 4 complex of silica-tetraethylene glycolic ether ( III ) was selected and used as a stable, cheap, and heterogeneous silica-based reagent for the selective mono- and dinitration of phenols and nitrosation of thiols
氯化硅与不同量的 H(OCH 2 CH 2 ) n OH (n = 2-4) 反应以提供基于二氧化硅的线性聚乙二醇和环状聚乙二醇醚。选择了二氧化硅-四甘醇醚 (III) 的 N 2 O 4 络合物,并将其用作一种稳定、廉价且非均相的二氧化硅基试剂,用于苯酚的选择性单硝化和二硝化以及硫醇的亚硝化。
Under anaerobic conditions S-nitrosothiols 1a-e undergo thermal decomposition by homolytic cleavage of the S-N bond; the reaction leads to nitric oxide and sulfanyl radicals formed in a reversible manner. The rate constants, k(t), have been determined at different temperatures from kinetic measurements performed in refluxing alkane solvents. The tertiary nitrosothiols 1c (k1(69 degrees C) = 13 x 10(-3)
在厌氧条件下,S-亚硝基硫醇1a-e通过SN键的均相裂解而发生热分解。该反应导致可逆地形成一氧化氮和亚硫烷基。速率常数k(t)已在不同温度下根据在回流烷烃溶剂中进行的动力学测量确定。叔亚硝基硫醇1c(k1(69摄氏度)= 13 x 10(-3)min(-1))和1d(k1(69摄氏度)= 91 x 10(-3)min(-1))分解更快比主要亚硝基硫醇1a(k1(69摄氏度)= 3.0 x 10(-3)min(-1))和1b(k1(69摄氏度)= 6.5 x 10(-3)min(-1))。活化能(E#= 20.5-22.8 Kcal mol(-1))已根据Arrhenius公式计算得出。在有氧条件下,S-亚硝基硫醇1a-e的降解是由N2O3催化的自催化链分解过程引起的。后者通过双氧与内源性和/或外源性一氧化氮反应形成。通过去除内源性一氧化氮或存在抗氧化剂(例如对甲酚,β-苯乙烯和BHT),强
Efficient Conversion of Thiols to S-Nitrosothiols with the 18-Crown-6 Complex of N2O4 as a New Nitrosating Agent
作者:N. Iranpoor、H. Firouzabadi、R. Heydari
DOI:10.1039/a904784k
日期:——
Gaseous N2O4 reacts with 18-crown-6 to afford a stable ionic complex of NO+·18-crown-6·H(NO3)2–; this complex is an efficient nitrosating agent for the conversion of thiols to their corresponding S-nitrosothiols in different organic solvents.