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Synthesis and chemosensitivity of a new iminium salt toward a cyanide anion.
Rao, Boddu Ananda,Lee, Jae-Young,Son, Young-A Pergamon 2014 Spectrochimica acta. Part A, Molecular and biomole Vol.127 No.-
<P>A short, high-yielding route to pyranylidene Iminium (Imi) salts using a new pyrylium salt reaction between N,N-Dimethylformamide (DMF) and acetic anhydride is reported. The Imi salt-sensing behavior toward various anions has been investigated using UV-Visible spectroscopy. The Imi salt demonstrates high selectively for CN(-) when various other anions, such as CN(-), Cl(-), Br(-), I(-), SCN(-), ClO4(-), NO3(-), HSO4(-), PF6(-) and N3(-), are present because it is highly reactive towards nucleophiles. The selective detection of CN(-) with the Imi unit gave rise to a significant hypochromic shift in the CH3CN solution at λmax=444nm and 423nm and creation of new peak at 252nm. These studies indicated that CN(-) had high affinity toward Imi, forming a 1:1 complex; this observation agrees with the current understanding of these materials.</P>
Hyuck Keun Oh*,Myoung Hwa Ku,Hai Whang Lee 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.6
Nucleophilic addition reactions of benzylamines (BA; XC6H4CH2NH2) to -cyano--phenylacrylamides (CPA; YC6H4CH=C(CN)CONH2) have been investigated in acetonitrile at 25.0 oC. The rate is first order with respect to BA and CPA and no base catalysis is observed. The addition of BA to CPA occurs in a single step in which the addition of BA to C of CPA and proton transfer from BA to C of CPA take place concurrently with a four-membered cyclic transition state structure. The magnitude of the Hammett (X) and Bršnsted (X) coefficients are rather small suggesting an early tansition state (TS). The sign and magnitude of the cross-interaction constant, XY (= 0.26), is comparable to those found in the normal bond formation processes in the SN2 and addition reactions. The normal kinetic isotope effect (kH/kD > 1.0) and relatively low H ¹ and large negative S ¹ values are also consistent with the mechanism proposed.
Oh, Hyuck-Keun,Ku, Myoung-Hwa,Lee, Hai-Whang Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.6
Nucleophilic addition reactions of benzylamines (BA; $XC_6H_4CH_2NH_2$) to $\alpha-cyano-\beta$-phenylacrylamides (CPA; $YC_6H_4CH=C(CN)CONH_2$) have been investigated in acetonitrile at 25.0 ${^{\circ}C}$. The rate is first order with respect to BA and CPA and no base catalysis is observed. The addition of BA to CPA occurs in a single step in which the addition of BA to $C_{\beta}$ of CPA and proton transfer from BA to $C_{\alpha}$ of CPA take place concurrently with a four-membered cyclic transition state structure. The magnitude of the Hammett ($\rho_X$) and Bronsted ($\beta_X$) coefficients are rather small suggesting an early tansition state (TS). The sign and magnitude of the crossinteraction constant, $\rho_XY$ (= −D0.26), is comparable to those found in the normal bond formation processes in the $S_N2$ and addition reactions. The normal kinetic isotope effect ($k_H/k_D\;{\gt}$ 1.0) and relatively low ${\Delta}H^{\neq}$ and large negative ${\Delta}S^{\neq}$ values are also consistent with the mechanism proposed.
Kinetic Studies on the Nucleophilic Addition Reactons of Vinylic β-Diketones
Oh, Hyuck-Keun,Lee, Jae-Myon Korean Chemical Society 2002 Bulletin of the Korean Chemical Society Vol.23 No.10
The kinetics of the addition of X-substituted benzylamines (BA) to Y-substituted Benzylideneacetylacetones (BAA) have been investigated in acetonitrile at $25.0^{\circ}C$. The reaction is studied under pseudo-first-order conditions by keeping a large excess of BA over BAA. The addition of BA to BAA occurs in a single step in which the addition of BA to $C_\alpha$ of BAA and proton transfer from BA to $C_\beta$ of BAA take place concurrently with a four-membered cyclic transition state structure. The magnitude of the Hammett ($p_X$) and Bronsted ($\beta_x$) coefficients are rather small suggesting an early tansition state (TS). The sign and magnitude of the cross-interaction constant, $p_{XY}$ (= -0.49), is comparatible to those found in the normal bond formation processes in the $S_N2$ and addition reactions. The normal kinetic isotope effect ($K_H/K_D$ > 1.0) and relatively low $\Delta$H^{${\neq}$}$ and large negative $\Delta$S^{${\neq}$}$ values are also consistent with the mechanism proposed.
Jang, K.S.,Shin, D.S.,Srisook, E.,Song, H.C.,Chi, D.Y. Pergamon Press 2016 Tetrahedron Vol.72 No.33
<P>Divergent functionalized 8-methoxyquinaldines were synthesized via regioselective debromination, 1,3 bromine shift process, aromatization with treatment of a strong base, nucleophilic substitution reaction at the C7 position using amines and cyanide as a nucleophile in the absence of a metal source and a catalyst from an unusual electrophilic aromatic addition (Ad(E)Ar) reaction products 7 and 8. In addition, quinaldine-7,8-dione was prepared by presence of CAN (ceric ammonium nitrate) in AcOH and H2O for 10 min at room temperature from N-(alkylamino)-8-methoxyquinalidines. During the Ad(E)Ar reaction, new stereoselective dearomatized addition products were generated via discriminative reaction routes depending on the methoxy and bromine occupancy position. The Ad(E)Ar reaction not only allowed for the functionalization of electron rich-fused heterocyclic arenes, but also provided a new synthetic route to an alternative mechanism for electrophilic aromatic substitution reactions. (C) 2016 Published by Elsevier Ltd.</P>
α-Phenyl-N-iso-propylnitrone 유도체에 대한 Potassium Cyanide의 친핵성 첨가반응 메카니즘과 반응 속도론적 연구
이광일,곽천근,장병만 경기대학교 1995 論文集 Vol.37 No.-
The rate constant of the nucleophilic addition of potassium cyanide to α-phenyl-N-iso-propylnitrone derivatives were determined at various pH and a rate equation which can be applied over wide pH range is obtained. Final product of the addition reaction was α-cyano-p-phenylbenzyliden-N-iso-propyl amine. Base on the rate equation, general base effect, substituent effect and final product, plausible mechanism of addition reaction have been proposed. Below pH 3.0, the reaction was initiated by the addition of netural hydrogen cyanide, and in the range of pH 3.0-10.0, proceeded by the competitive addition of hydrogen cyanide and cyanide anion. Above the pH 10.0, the reaction proceeded through the addition of cyanide anion.
Hwang, Jae-young,Yang, Ki-yull,Koo, In-Sun,Sung, Dae-Dong,Lee, Ik-choon Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.5
Nucleophilic addition reactions of p-substitutedbenzylamines $(XC _6H_4CH _2NH _2)$ to $\alpha$-phenyl-$\beta$-thiophenyl-acrylonitriles ($YC _4SH _2CH=C(CN)C_6H_4$Y') have been studied in acetonitrile at 25.0, 30.0, and 35.0 ${^{\circ}C}$. The reactions take place in single step in which the $C_\beta$ -N bond formation and proton transfer to $C_\alpha$ of $\alpha$-phenyl-$\beta$-thiophenylacrylonitriles occur concurrently with four-membered cyclic transition structure. These mechanistic conclusions are drawn based on (i) the large negative $\rho$x and large positive $\rho$Y' values and also large magnitude of $\rho$X, (ii) the negative sign and large magnitude of the cross-interaction constants ($\rho$XY), (iii) the normal kinetic isotope effects ($k_H/k_D$ > 1.0), and (iv) relatively low $\Delta H ^\neq$ and large negative $\Delta S ^\neq$ values.
Oh, Hyuck-Keun,Kim, Tae-Soo,Lee, Hai-Whang,Lee, Ik-Choon Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.2
Nucleophilic addition reactions of benzylamines $(XC_6H_4CH_2NH_2)$ to benzylidene Meldrum's acids (BMA; $YC_6H_4CH=C(COO)_2C(CH_3)_2$) have been investigated in acetonitrile at 20.0 ℃. The rates of addition are greatly enhanced due to the abnormally high acidity of Meldrum's acid. The magnitudes of the Hammett $({\rho}_X\;and\;{\rho}_Y)$ and Bronsted $({\rho}_X$)$ coefficients are rather small suggesting an early transition state. The sign and magnitude of the cross-interaction constant, ${\rho}_{XY}$ (= -0.33), and kinetic isotope effects $(k_H/k_D\;{\stackrel}{~}{=}\;1.5-1.7)$ involving deuterated benzylamine nucleophilies $(XC_6H_4CH_2ND_2)$ are indicative of hydrogen-bonded cyclic transition state. The activation parameters, ${\Delta}H^{\neq}\;{\stackrel}{~}{=}\;4\;kcal\;mol^{-1}\;and\;{\Delta}S^{\neq}\;{\stackrel}{~}{=}\;-37\;e.u.$, are also in line with the proposed mechanism.