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91.
Mekhman S. Yusubov Elena N. Tveryakova Elena A. Krasnokutskaya Irina A. Perederyna Viktor V. Zhdankin 《合成通讯》2013,43(8):1259-1265
A simple and environmentally safe general method of iodination of aromatic substrates under sovent‐free conditions using the I2/AgNO3 combination in a solid state is reported. Both activated and deactivated aromatic compounds afford the respective aryl iodides in generally high yields (80–90%). 相似文献
92.
Gowri Sridhar 《合成通讯》2013,43(1):21-29
The 1,3‐dipolar cycloaddition of an azomethine ylide, generated from isatin and sarcosine by a decarboxylative route with various p‐substituted 3,5 bis(aryl methylidene)N‐methyl‐4‐piperidinones in refluxing methanol, proceeded regioselectively to give novel dispiroheterocycles. The product on subsequent annulation with hydrazine hydrate afforded 1‐N‐methyl‐spiro[2.3′]oxindole‐spiro[3.7″](3″‐aryl)‐5″‐methyl‐3″,3a″,4″,5″,6″,7″‐hexahydro‐2H‐pyrazolo[4,3‐c]pyridine‐4‐aryl‐pyrrolidines in good yield. 相似文献
93.
A new and efficient method to synthesize a 3,3,6,6,9‐aryl‐1,8‐dioxo‐octahydroxanthene derivative using diammonium hydrogen phosphate as catalyst was performed in water at room temperature in a short periods. 相似文献
94.
Suresh B. Waghmode Ganesh Mahale Viraj P. Patil Kartik Renalson Dharmendra Singh 《合成通讯》2013,43(24):3272-3280
A rapid method for selective cleavage of aryl methylethers can be achieved in the presence of a protic acid and a catalytic amount of phase-transfer catalyst (Aliquat-336). Aliquat-336 accelerates the rate of reaction and affords the corresponding phenols in excellent to good yields on a wide variety of substrates. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
95.
A transition-metal-free method for the synthesis of indolines has been developed. In the presence of K2CO3, the cyclization reaction of N-(ortho-chloromethyl)aryl amides and iodonium ylides proceeded smoothly at room temperature in moderate to good yields. 相似文献
96.
Benjamin M. Gridley Dr. Graeme J. Moxey Dr. William Lewis Prof. Alexander J. Blake Dr. Deborah L. Kays 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(34):11446-11453
The synthesis and characterization of the first series of low‐coordinate bis(terphenyl) complexes of the Group 12 metals, [Zn(2,6‐Naph2C6H3)2] ( 1 ), [Cd(OEt2)(2,6‐Naph2C6H3)2] ( 2 ) and [Hg(OEt2)(2,6‐Naph2C6H3)2] ( 3 ) (Naph=1‐C10H7) are described. The naphthyl substituents of the terphenyl ligands confer considerable steric bulk, and as a result of limited flexibility introduce multiple conformations to these unusual systems. In the solid state, complex 1 features a two‐coordinate Zn centre with the ligands oriented in a syn/anti conformation, whereas the three‐coordinate distorted T‐shaped complexes 2 and 3 feature the ligands in the syn/syn configurations. The results of DFT calculations are in good agreement with the solid‐state configurations for these complexes and support the spectroscopic measurements, which indicate several conformers in solution. 相似文献
97.
An efficient and convenient method for the synthesis of aryl hydrazines has been developed via copper-catalyzed cross-coupling of aryl bromides and hydrazine with a readily accessible ligand and water as a solvent. The multigram scale procedure is applicable to aryl bromides bearing both moderately electron-donating and electron-withdrawing substituents in the aromatic nucleus. No column chromatography is required to obtain aryl hydrazine hydrochlorides in good yields. 相似文献
98.
The gas‐phase acidities (GA) of various aryl‐substituted fluoroalkanes, XC6H4CH(R1)R2, were calculated at the B3LYP/6‐311 + G(d,p)//B3LYP/6‐311 + G(d,p). The acidity values of alkanes having a common substituent X varied significantly with the change of R1 and R2. Their changes in acidity of 1 and 2 having two strong electron‐withdrawing groups (CF3 or C2F5) at the deprotonation site and 8 , 9 , 10 , 11 having no fluorine atom at β‐position were linearly correlated with the corrected number of fluorine atoms contained in the fluorinated alkyl group (R2 > 0.999). On the other hand, the GA values of β‐fluorine substituted alkanes ( 3 , 4 , 5 , 6 , 7 ) deviated in a stronger acid direction from the line. The enhanced acidity was attributed to the additional stabilization of the conjugate anion caused by the β‐fluorine negative hyperconjugation. The magnitude of β‐fluorine negative hyperconjugation of the fluorinated alkyl group (ΔGoβ‐F) given by the deviations from the line decreased with increasing electron‐withdrawing ability of substituent X on the benzene ring, indicating that β‐fluorine negative hyperconjugation competes with the electronic effect of the substituent X. The GAel values obtained by subtraction ΔGoβ‐F from the apparent GA value were successfully correlated in terms of the Yukawa–Tsuno equation. The obtained ρel and r?el values were linearly related to the GAel value of the respective phenyl‐substituted fluoroalkanes, supporting our previous conclusion that the ρ and r? values for the substituent effect caused by the electronic effects of the substituent on the acidity are determined by the thermodynamic stability of the parent ion (ring substituent = H). Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
99.
Jordan De Jesus Silva Niccolò Bartalucci Benson Jelier Samantha Grosslight Tobias Gensch Claas Schünemann Bernd Müller Paul C. J. Kamer Christophe Copéret Matthew S. Sigman Antonio Togni 《Helvetica chimica acta》2021,104(12):e2100200
A synthetic method for the palladium-catalyzed cyanation of aryl boronic acids using bench stable and non-toxic N-cyanosuccinimide has been developed. High-throughput experimentation facilitated the screen of 90 different ligands and the resultant statistical data analysis identified that ligand σ-donation, π-acidity and sterics are key drivers that govern yield. Categorization into three ligand groups – monophosphines, bisphosphines and miscellaneous – was performed before the analysis. For the monophosphines, the yield of the reaction increases for strong σ-donating, weak π-accepting ligands, with flexible pendant substituents. For the bisphosphines, the yield predominantly correlates with ligand lability. The applicability of the designed reaction to a wider substrate scope was investigated, showing good functional group tolerance in particular with boronic acids bearing electron-withdrawing substituents. This work outlines the development of a novel reaction, coupled with a fast and efficient workflow to gain understanding of the optimal ligand properties for the design of improved palladium cross-coupling catalysts. 相似文献
100.
以酰胺-噁唑啉为辅助基团,在廉价的醋酸铜促进下,实现了酰胺衍生物C(sp2)—H键与芳基硫醇S—H键的脱氢偶联反应;以中等到优秀的产率(最高可达90%)简单高效地合成了一系列双硫化的酰胺衍生物.值得一提的是,底物范围并不局限于各种取代苯基酰胺化合物,吡啶基酰胺化合物也可以兼容.该反应的特点是:金属廉价、底物范围广、反应条件温和、无需外加配体、空气作为氧化剂、区域选择性好(仅酰胺基团邻位的C—H键发生反应,而噁唑啉基团邻位的C—H键不发生反应);此外,克级规模的反应表明了其在合成中的实用性. 相似文献