• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1829-1834
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• 2013

The nucleophilic substitution reactions of Y-aryl ethyl isothiocyanophosphates with substituted X-anilines and deuterated X-anilines were investigated kinetically in acetonitrile at $75.0^{\circ}C$. The free energy relationships with X in the nucleophiles exhibited biphasic concave downwards with a break point at X = H. A stepwise mechanism with rate-limiting bond formation for strongly basic anilines and with rate-limiting bond breaking for weakly basic anilines is proposed based on the negative and positive ${\rho}_{XY}$ values, respectively. The deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) changed gradually from primary normal with strongly basic anilines, via primary normal and secondary inverse with aniline, to secondary inverse with weakly basic anilines. The primary normal and secondary inverse DKIEs were rationalized by frontside attack involving hydrogen bonded, four-center-type TSf and backside attack involving in-line-type TSb, respectively.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1879-1884
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• 2012

The kinetic studies on the reactions of dipropyl chlorophosphate (3O) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) have been carried out in acetonitrile at $55.0^{\circ}C$. The obtained deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are primary normal ($k_H/k_D$ = 1.09-1.01) with the strongly basic anilines while secondary inverse ($k_H/k_D$ = 0.74-0.82) with the weakly basic anilines. The steric effects of the two ligands on the rates are extensively discussed for the anilinolyses of the ($R_1O$)($R_2O$)P(=O or S)Cl-type chlorophosphates and chlorothiophosphates. A concerted mechanism is proposed with a frontside nucleophilic attack involving a hydrogen-bonded four-center-type transition state for the strongly basic anilines and with a backside attack transition state for the weakly basic anilines on the basis of the DKIEs, primary normal and secondary inverse with the strongly and weakly basic anilines, respectively.

• Bulletin of the Korean Chemical Society
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• v.17 no.12
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• pp.1132-1135
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• 1996

N-Substituted anilines react with triethanolamine at 180℃ in the presence of a catalytic amount of tris(triphenylphosphine)ruthenium(Ⅱ) chloride to give the corresponding 1-substituted indoles in good to high yields. Similar treatment of the anilines with N-benzyldiethanolamine or triisopropanolamine in place of triethanolamine also affords the indoles in good yields. An intermolecular alkyl group transfer between anilines and alkanolamines is assumed to be the key step of these reactions.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2306-2310
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• 2011

The nucleophilic substitution reactions of diethyl thiophosphinic chloride with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at 55.0 $^{\circ}C$. The values of deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) invariably increase from secondary inverse ($k_H/k_D$ < 1) to primary normal (kH/kD > 1) as the nucleophiles change from the strongly basic to weakly basic anilines. The secondary inverse with the strongly basic anilines and primary normal DKIEs with the weakly basic anilines are rationalized by the gradual transition state (TS) variation from a predominant backside attack, via invariably increasing the fraction of a frontside attack, to a predominant frontside attack, in which the reaction mechanism is a concerted $S_N2$ pathway. A frontside attack involving a hydrogen bonded, four-center-type TS is substantiated by the primary normal DKIEs.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.394-398
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• 2013

An efficient process for the synthesis of N-azaaryl anilines via Smiles rearrangement as a tool. A variety of N-azaaryl anilines were generated by the reaction of substituted phenols, substituted anilines, aminopyridines and chloroacetyl chloride or pyridols, under base condition in good to excellent yields.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.663-669
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• 2012

The nucleophilic substitution reactions of dibutyl chlorophosphate (3) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The obtained deuterium kinetic isotope effects (DKIEs; kH/kD) are secondary inverse ($k_H/k_D$ = 0.86-0.97) with the strongly basic anilines while primary normal ($k_H/k_D$ = 1.04-1.10) with the weakly basic anilines. The DKIEs, steric effects of the two ligands, activation parameters, cross-interaction constants, variation trends of the kH/kD values with X, and mechanism are discussed for the anilinolyses of the nine ($R_1O$)($R_2O$)P(=O)Cl-type chlorophosphates. A concerted mechanism is proposed with a backside nucleophilic attack transition state for the strongly basic anilines and with a frontside attack involving a hydrogen-bonded four-center-type transition state for the weakly basic anilines on the basis of the magnitudes, secondary inverse and primary normal, and variation trends of the $k_H/k_D$ values with X.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3355-3360
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• 2011

The nucleophilic substitution reactions of 1,2-phenylene phosphorochloridate (1) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $-15.0^{\circ}C$. The studied substrate of 1,2-phenylene phosphorochloridate is cyclic five-membered ring of phosphorus ester, and the anilinolysis rate of 1 is much faster than its acyclic analogue (4: ethyl phenyl chlorophosphate) because of extremely small magnitude of the entropy of activation of 1 compared to 4. The Hammett and Bronsted plots exhibit biphasic concave upwards for substituent X variations in the nucleophiles with a break point at X = 3-Me. The values of deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) change from secondary inverse ($k_H/k_D$ < 1) with the strongly basic anilines to primary normal ($k_H/k_D$ > 1) with the weakly basic anilines. The secondary inverse with the strongly basic anilines and primary normal DKIEs with the weakly basic anilines are rationalized by the transition state (TS) variation from a predominant backside attack to a predominant frontside attack, in which the reaction mechanism is a concerted $S_N2$ pathway. The primary normal DKIEs are substantiated by a hydrogen bonded, four-center-type TS.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1997-2002
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• 2011

The nucleophilic substitution reactions of dicyclohexyl phosphinic chloride [3; $cHex_2$P(=O)Cl] with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at 60.0 $^{\circ}C$. The anilinolysis rate is too slow to be rationalized by the stereoelectronic effects. The rate is contrary to expectations for the electronic influence of the two ligands and exhibits exceptionally great negative deviation from the Taft's eq. The deuterium kinetic isotope effects (DKIEs) involving deuterated anilines invariably change from primary normal ($k_H/k_D$ > 1; max $k_H/k_D$ = 1.10 with X = 4-MeO) with the strongly basic anilines (X = 4-MeO, 4-Me, 3-Me) to secondary inverse ($k_H/k_D$ < 1; min $k_H/k_D$ = 0.673 with X = 3-Cl) with the weakly basic anilines (X = H, 4-F, 4-Cl, 3-Cl). A concerted $S_N2$ mechanism is proposed on the basis of both secondary inverse and primary normal DKIEs. The obtained DKIEs imply that the fraction of a frontside attack increases as the aniline becomes more basic. A hydrogen-bonded, four-center-type transition state is suggested for a frontside attack, while the trigonal bipyramidal pentacoordinate transition state is suggested for a backside attack.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.753-757
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• 2014

The nucleophilic substitution reactions of Y-aryl N,N-dimethyl phosphoroamidochloridates with substituted anilines and deuterated anilines are kinetically investigated in acetonitrile at $65.0^{\circ}C$. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed based on the positive ${\rho}_{XY}$ value. The deuterium kinetic isotope effects involving deuterated anilines show secondary inverse with all the nucleophiles, rationalized by a dominant backside nucleophilic attack.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1016-1022
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• 2014

The kinetic studies on the reactions of O-methyl N,N-diisopropylamino phosphonochloridothioate with X-anilines and X-pyridines have been carried out in acetonitrile. The free energy relationship with X in the anilines exhibits biphasic concave upwards with a break region between X = (H and 4-F), giving unusual negative ${\beta}_X$ and positive ${\rho}_X$ values with weakly basic anilines. The unusual phenomenon is rationalized by isokinetic relationship. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed based on the selectivity parameter and variation trend of the deuterium kinetic isotope effects with X. The free energy relationship with X in the pyridines exhibits biphasic concave upwards with a break point at X = 3-MeO. A concerted mechanism is proposed based on relatively small ${\beta}_X$ value, and frontside and backside nucleophilic attack are proposed with strongly and weakly basic pyridines, respectively.