共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
A simple, convenient, and efficient one-pot method for the preparation of benzofuran is reported. Sonogashira coupling reaction of aryl iodides with 2-methyl-3-butyn-2-ol was used as an acetylene source in the presence of Pd(PPh3)2Cl2 and CuI. Deprotection of the acetylene moiety in the same pot using a strong base and the second Sonogashira coupling/cyclization of and substituted o-iodophenols led to the formation of the appropriate benzo[b]furans. These protocols also can be used in the synthesis of natural products and indoles. 相似文献
4.
A facile synthesis of 2-substituted benzo[b]thiophen-3-ols in a simple reaction system is reported with water as the only media. Density functional theory (DFT) investigations suggest two pathways comparable in energetics: A neutral pathway with concerted C-C bond formation and hydrogen transfer and an anionic pathway with anion attack to the carbonyl group. Studies indicate that water plays crucial mechanistic roles in both cases. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
5.
Claudia Feberero Cintia Virumbrales Carlos Sedano Lorena Renedo Samuel Surez-Pantiga Roberto Sanz 《Molecules (Basel, Switzerland)》2022,27(2)
A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[b]furans has been developed employing simple and easily available starting materials such as O-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed ortho-lithiation process, which uses the carbamate as the directed metalation group, was crucial in providing access to O-2-alkynylaryl N,N-diethyl carbamates by a direct alkynylation of the o-lithiated carbamate, with arylsulfonylalkynes as electrophilic reagents. Cyclization of the generated o-alkynylaryl carbamates was successfully accomplished through a strategy involving in situ carbamate alkaline hydrolysis under conventional heating or microwave irradiation, coupled with a subsequent heterocyclization step delivering the desired benzo[b]furans. A wide variety of new halobenzo[b]furans has been synthesized and their utility has been demonstrated by their further transformation. 相似文献
6.
A facile synthesis of benzofuro[2,3‐c]pyridines has been achieved under mild conditions by using ammonium acetate as the nitrogen source through intramolecular cascade annulation. This reaction could efficiently construct pyridine ring and furan ring in one step. Moreover, the key annulation step was demonstrated through dihydrobenzofuran intermediates. 相似文献
7.
3‐Amino‐benzo[d]imidazo[2,1‐b]thiazoles were synthesized in moderate to good yields in the presence of NH4Cl via a one pot procedure. All the products were characterized by 1H NMR, IR, HRMS. 相似文献
8.
An Iron‐Catalyzed Cascade Approach to Benzo[b]carbazole Synthesis Followed by 1,4‐Sulfonyl Migration 下载免费PDF全文
Siva Senthil Kumar Boominathan Gopal Chandru Senadi Dr. Jaya Kishore Vandavasi Dr. Jeff Yi‐Fu Chen Prof. Dr. Jeh‐Jeng Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(8):3193-3197
A simple and straightforward approach was developed to construct 5H‐benzo[b]carbazole derivatives by iron catalysis in a cascade sequence. The notable features of this work include an atom‐economical cascade sequence, unprecedented 1,4‐sulfonyl migration, tolerance of a variety of functional groups, good yields, and an economical catalytic system. 相似文献
9.
A metal-free approach for the synthesis of seven-membered N-heterocycles has been developed by the I2-promoted intramolecular cross-coupling/annulation of butenyl anilines. This cyclization reaction involves C−H activation and C−C bond formation and exhibits good functional group tolerance. A series of benzo[b]azepine derivatives are obtained in moderate to good yields. 相似文献
10.
可见光驱动光环化的荧光turn-on型二芳基乙烯分子开关是超分辨显微成像的理想材料, 但目前关于该类型分子的报道仍较少. 本工作合成了一种基于苯并[b]萘并[1,2-d]噻吩(BNTP)的405 nm可见光驱动光环化的荧光turn-on型二芳基乙烯分子BNTP-BTTO4, 同时系统研究了该分子的光物理性能与稳定性, 并借助密度泛函理论(DFT)计算厘清了分子实现可见光驱动光环化及荧光turn-on原因. 另外, 本研究发现BNTP引入后分子表现出比参比分子Ph-BTTO4更优异的抗疲劳性、热稳定性和光稳定性, 尤其是在历经200 min 405 nm可见光照射后, BNTP-BTTO4(c)吸收强度只下降4%, 光稳定性大幅提升. 本研究为设计开发性能优异的可见光驱动光环化的荧光turn-on型二芳基乙烯提供了新的思路. 相似文献
11.
Base-induced coupling/cyclization stepwise [3+2] annulation of α-sulfonylacetamide with (Z)-2-bromoacrylates yielded polysubstituted pyroglutamates with three contiguous chiral centers with trans-trans orientation in a one-pot synthesis. The pyrrolizidine skeleton was obtained via the ring-closing metathesis (RCM) method. This facile strategy was used to synthesize psudoheliotridane. 相似文献
12.
以焦性没食子酸、4-羟基苯甲醛和酚为原料, 以邻碘代苯酚与苯乙炔衍生物的Sonogashira偶联及其连串化反应生成苯并呋喃环为关键步骤, 设计合成了一系列2-(2 ,6 -二烷氧基苯基)苯并呋喃衍生物, 并对产物进行了1H NMR, 13C NMR, MS等表征. 相似文献
13.
Mao Zhang Fenfen Yang Xiang Guan Mingshan Shuai Qingqing Zhang Prof. Xiaozhong Fu Prof. Yuanyong Yang Prof. Meng Zhou Prof. Bin He Prof. Yonglong Zhao 《European journal of organic chemistry》2023,26(15):e202300159
A simple base-promoted [2+1] annulation of indolin-3-ones and bromosulfonium salts has been developed in this article. This strategy uses simple and easily prepared indolin-3-ones 1 as C1 synthons and bromosulfonium salts 2 as C2 synthons under mild reaction conditions, and 33 examples of C2-spirocyclopropyl-indolin-3-ones were obtained with up to 99 % yield and >20 : 1 dr. 相似文献
14.
T. A. Stroganova A. V. Butin V. G. Kul'nevich 《Chemistry of Heterocyclic Compounds》2001,37(8):939-943
New derivatives of benzo[b]furan were obtained during successive bromination and dehydrobromination of alkanones containing a gem-difurylmethyl fragment. A mechanism is proposed for the transformations that occur. 相似文献
15.
Qian Zhao Chao Qian Xin-Zhi Chen 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):873-878
Abstract A convenient and efficient synthesis of 2-substituted benzo[b]thiophenes is described. This one-step reaction of alkylthiobenzaldehyde and activated electrophiles proceeded smoothly in toluene at 120 °C with magnesium oxide as a catalyst. The target 2-substituted benzo[b]thiophenes are obtained in moderate yields and the side reaction is inhibited via azeotropic distillation. According to the experiments, a plausible mechanism is presented. 相似文献
16.
17.
Efficient, mild, and quantitative procedures for the synthesis of functionalized benzo[c]chromeno[2,3-a]phenazine derivatives by one-pot, four-component condensation of 2-hydroxynaphthalene-1,4-dione, 1,2-phenylenediamines, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds have been developed using catalytic amounts of H2SO4 and phosphotungstic acid in EtOH/H2O (1:1) under reflux and also with [NMP]H2PO4, which acts as catalyst and medium at 80 °C. The reaction avoids tedious workup procedure due to the direct precipitation of products from the reaction medium. The present finding provides promising synthetic strategies for the synthesis of libraries with functional group diversity. 相似文献
18.
Attunuri Nagireddy Dattatri Jagadeesh Babu Nanubolu Dr. Maddi Sridhar Reddy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(70):17570-17575
An unprecedented [2+2+1] hydrative annulation of 1,6-enynes with terminal alkynes is achieved using catalytic cationic Rh(I). Thus, a modular assembly of cyclopenta[b]benzofuranols with two consecutive quarternary stereocenters is achieved from readily available alkynes. The reaction is proposed to go through a sequence of 5-membered rhoda-cycle formation, regioselective acetylene insertion, 1,5 H-shift, substrate controlled stereoselective addition of water molecule followed by 1,2-rhodium migration gave contracted rhoda-cycle D and reductive elimination. Necessary control/labelling experiments were conducted to gain insight in to the mechanism. 相似文献
19.
B.A.Bhanu Prasad 《Tetrahedron letters》2004,45(6):1137-1141
An efficient synthesis of 2,4-disubstituted 1H-imidazolines from aziridines and nitriles in the presence of BF3-Et2O or triethyloxonium tetrafluoroborate has been described. The reaction proceeds via a [3+2]-cycloaddition reaction. Most of the nitriles successfully underwent cycloaddition reactions with aziridines even at room temperature in a very short time. 相似文献