InCl3‐Driven Regioselective Synthesis of Functionalized/Annulated Quinolines: Scope and Limitations

The efficient, regioselective synthesis of functionalized/annulated quinolines was achieved by the coupling of 2‐aminoaryl ketones with alkynes/active methylenes/α‐oxoketene dithioacetals promoted by InCl₃ in refluxing acetonitrile as well as under solvent‐free conditions in excellent yields. This transformation presumably proceeded through the hydroamination–hydroarylation of alkynes, and the Friedländer annulation of active methylene compounds and α‐oxoketene dithioacetals with 2‐aminoarylketones. In addition, simple reductive and oxidative cyclization of 2‐nitrobenzaldehyde and 2‐aminobenzylalcohol, respectively, afforded substituted quinolines. Systematic optimization of the reaction parameters allowed us to identify two‐component coupling (2CC) conditions that were tolerant of a wide range of functional groups, thereby providing densely functionalized/annulated quinolines. This approach tolerates the synthesis of various bioactive quinoline frameworks from the same 2‐aminoarylketones under mild conditions, thus making this strategy highly useful in diversity‐oriented synthesis (DOS). The scope and limitations of the alkyne‐, activated methylene‐, and α‐oxoketene dithioacetal components on the reaction were also investigated.     

Organocatalyzed Synthesis of Functionalized Quinolines

As one of the most widely investigated compound skeleton, quinolines possess important medicinal and biological activities. As such, a great number of literatures, including reviews, have reported various methodologies to construct quinolines. Recently, organocatalyzed reactions have attracted the attention of organic chemists due to its being “green” because the reactions avoid the use of toxic metals. In this review, various distinctive contributions are surveyed with specific emphasis on organocatalyzed reactions for quinoline core constructions.     

Synthesis of 2,3‐Disubstituted Quinolines via Ketenimine or Carbodiimide Intermediates

Cyclopenta[b]quinolines and cyclohexa[b]quinolines were prepared via the reactions of α‐diazo ketones with N‐(2‐cyclopropylidenemethylphenyl)phosphanimines and N‐(2‐cyclobutylidenemethylphenyl) phosphanimine, respectively. The reaction proceeds in a cascade involving ketenimine formation, 6 π‐electron ring closure, and 1,3‐alkyl shift. A similar approach was developed for the synthesis of dihydropyrrolo‐[2,3‐b]quinolines from N‐(2‐cyclopropylidenemethylphenyl)phosphanimines and isocyanates.     

生物分子辅助的纳米材料绿色合成

纳米材料绿色合成的标准是合成需使用对环境无污染的溶剂体系、还原剂以及无毒的稳定剂来进行.生物分子具备有机和无机质导向生成的能力,且具有热和化学稳定性、容易获得、价格便宜,最重要的是对环境无污染,可用于纳米材料的绿色制备.本文就笔者在生物分子辅助绿色合成纳米材料方面的研究成果做一汇总和介绍.     

A Novel Green Synthesis of Quinolines through Acid-catalyzed Friedlander Reaction in Ionic Liquids

Quinoline derivatives were efficiently prepared through acid-catalyzed Friedlander reaction in ionic liquid ([bmim] [BF4]). It is shown that the proposed method is operationally simple and environmentally benign in that the reaction media and the catalyst can be recovered and be reused effectively for at least four times.     

Green and Efficient Synthesis of 3-Pyrazolyl Indoles in Water

A green and efficient synthesis of 3-pyrazolyl indoles was developed by the cyclocondensation reaction of β-ethylthio-β-indolyl-α,β-unsaturated ketones with semicarbazide hydrochloride as hydrazine equivalent in the presence of 3 equiv. of PEG-400(1a/PEG mole ratio of 1:3) in reflux water. This procedure did not require toxic hydrazine and product purification, eliminating the use of toxic liquid chemicals.     

Microwave-Assisted Efficient and Green Synthesis of Hydroxyxanthone in Water

An efficient and green procedure has been developed for the synthesis of hydroxyxanthones from substituted 2,2′-dihydroxybenzophenone precursors via microwave-assisted base-catalyzed cyclization in water. This method provides excellent yields of products in a short time, making it a useful strategy for the synthesis of structurally diverse hydroxyxanthones.     

ZnO: An Ecofriendly,Green Nano‐catalyst for the Synthesis of Pyrazole Derivatives under Aqueous Media

An efficient nano ZnO catalyzed green protocol for the synthesis of pyrazol derivatives by condensation of different substituted phenyl hydrazines/semicarbazide/thiosemicarbazide with 1,3‐diketone/ketoester at ambient temperature has been achieved. ZnO nanocatalyst was prepared by low temperature solution combustion method. From the Scherrer method the crystallite size of ZnO was estimated and found to be in the range of 30–50 nm. The main advantage of this protocol is an excellent yield, short reaction time and easy work up procedure. The catalyst was found to be reusable up to five catalytic cycles without any appreciable loss in activity of the catalyst.     

Catalyst‐Driven Scaffold Diversity: Selective Synthesis of Spirocycles,Carbazoles and Quinolines from Indolyl Ynones

Medicinally relevant spirocyclic indolenines, carbazoles and quinolines can each be directly synthesised selectively from common indolyl ynone starting materials by catalyst variation. The high yielding, divergent reactions all proceed by an initial dearomatising spirocyclisation reaction to generate an intermediate vinyl–metal species, which then rearranges selectively by careful choice of catalyst and reaction conditions.     

离子液体的绿色合成及环境性质

针对离子液体的绿色合成及应用过程中的环境性质,对离子液体常规合成的改进、无溶剂的微波和超声辅助合成等方面的研究进展进行了总结,对离子液体在生物体内的累积程度、离子液体的毒性和降解性等方面的研究进行了介绍。     

InCl3·4H2O Promoted Green Preparation of Xanthenedione Derivatives in Ionic Liquids

Xanthenediones derivatives have attracted considerable interests in recent times because they constitute a structural unit in a number of natural products1 and have been used as versatile synthons due to the inherent reactivity of the inbuilt pyran ring2. The conventional syntheses of xanthenediones were acid or base catalyzed condensation of appropriate active methylene carbonyl compounds with aldehydes3. However, many of these procedures involved longer reaction times,low yields and side reactions of aldehydes. In recent years, room temperature ionic liquids (RTILs) have been used as novel green reaction media4. Considering that InCl3 is an efficient Lewis acid catalyst used in promoting many organic reactions, especially in several condensation processes, we herein wish to report a very simple and green method for the preparation of poly-hydrogenated xanthenediones through InCl3·4H2O promoted cascade reaction of aldehydes and 5,5-dimethyl-l,3-cyclohexanedione in ionic liquid,1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]). The preparative process presented here is operationally simple, environmentally benign and has the advantage of enhanced atom utilization. Furthermore, the solvent and the catalyst used can be recovered easily and reused efficiently.     

Synthesis of Polysubstituted Quinolines Using Cyanuric Chloride as a Catalyst Under Aqueous Conditions

A mild, eco‐friendly and efficient route for the synthesis of quinolines and polycyclic quinolines via Friedländer annulation using cyanuric chloride as a catalyst under aqueous conditions is described.     

Facile Synthesis of Size-Controlled Nitrogen-Doped Mesoporous Carbon Nanosphere Supported Ultrafine Ru Nanoparticles for Selective Hydrogenation of Quinolines

Nitrogen-doped mesoporous carbon nanosphere (NMCS) with tunable sizes and uniform mesoporosity was synthesized by a facile soft-templating method. During the synthesis, F127 (PEO–PPO–PEO triblock copolymer) could be used not only as a soft template to generate the mesostructure but also as a size-control agent to tailor the size of NMCS in a relatively wide range of 100 to 700 nm. In addition, the synthesis process was simple and suitable for large-scale production. Moreover, the NMCS was used as support of ultrafine Ru nanoparticles (Ru/NMCS), which exhibited good catalytic performances for selective hydrogenation of quinolones. It is expected that the simple synthetic strategy for the NMCS can generate extensive interest in many catalysis and sorption applications.     

纳米金催化的绿色合成与清洁反应研究新进展

近年来,基于多相纳米金(Au)催化的绿色合成与清洁反应研究引起了人们的广泛关注。与传统的铂族金属催化剂相比,纳米Au催化剂在控制反应选择性、高收率获得目标产物以及实现高效简约的一锅法串联反应合成等符合"原子经济"及"步骤经济"等绿色化学理念的新反应及新过程方面展现了其独特的优势,已成为当前绿色催化领域研究的热点和前沿。主要综述了我们研究小组在纳米Au催化绿色合成领域,尤其是利用纳米Au催化高效制取含氮精细有机化合物及生物质资源高值化利用方面所取得的研究进展,介绍了各类反应的特点、优势及在合成中的应用。     

Green,Microwave-Assisted Approach to the Synthesis of Arylidene-Substituted Spiro[4,5]decan-8-one Derivatives in Water

A green approach to the synthesis of arylidene-substituted spiro[4,5]decan-8-one derivatives was successfully realized via the mild, base-catalyzed reaction of aromatic aldehydes with 1,4-dioxa-spiro[4.5]decan-8-one in water under microwave irradiation. This protocol has the prominent advantages of environmental friendliness, short reaction time, excellent yields, low cost, easy operation, and broad scope of applicability.     

Green Synthesis of Magnetic Zeolite LTA using NaOH Activated Fly Ash

The magnetic zeolite LTA was successfully synthesized using NaOH activated fly ash. The properties of the magnetic zeolite LTA were characterized by XRD, FTIR, SEM, TEM, BET, and VSM. We can be concluded that the synthesized composite consists of zeolite LTA and magnetic Fe₃O₄ nanoparticle. The nitrogen adsorption technique confirmed that the magnetic zeolite LTA exhibits a specifific surface area of 10.0183 m² · g^–1, which is much larger than that of the fly ash. VSM result confirms that the magnetization saturation value of the magnetic zeolite LTA is 10.06 emu · g^–1. Therefore, the magnetic zeolite LTA could be easily separated from the liquid phase using a magnet.     

一步法绿色氧化环己烷制备己二酸的研究进展

己二酸具有巨大的工业用途及需求,然而传统的制备方法存在着高能耗、高污染等缺点,开发更加清洁绿色的制备方法是大势所趋。本文主要介绍了国内外以绿色清洁氧化剂如O2(空气)、H2O2、O3氧化环己烷一步制备己二酸的研究进展。     

Gold‐Catalyzed Synthesis of Quinolines from Propargyl Silyl Ethers and Anthranils through the Umpolung of a Gold Carbene Carbon

A gold‐catalyzed cascade annulation of propargylic silyl ethers with anthranils proceeds through a sequential ring opening/1,2‐H‐shift/protodeauration/Mukaiyama aldol cyclization. This method offers a regiospecific and modular access to 2‐aminoquinolines and other quinoline derivatives under mild conditions and with a broad functional‐group tolerance. The conversion is possible on a gram scale, which underlines the synthetic practicability of this methodology. The versatility of the obtained scaffold has been demonstrated by useful postfunctionalization.