The Mannich Reaction of Butanone,Aromatic Aldehydes and Aromatic Amines

Under the catalysis of small amount of concentrated hydrochloric acid, the Mannich reaction of butanone, aromatic aldehydes and aromatic amines can be carried out directly at 0–20°C. Twelve corresponding Mannich bases (1), 1-aryl-1-arylamino-3-pentanones, were prepared in high yields.     

Reduction of aromatic compounds with Al powder using noble metal catalysts in water under mild reaction conditions

In water, Al powder becomes a powerful reducing agent, transforming in cyclohexyl either one or both benzene rings of aromatic compounds such as biphenyl, fluorene and 9,10-dihydroanthracene under mild reaction conditions in the presence of noble metal catalysts, such as Pd/C, Rh/C, Pt/C, or Ru/C. The reaction is carried out in a sealed tube, without the use of any organic solvent, at low temperature. Partial aromatic ring reduction was observed when using Pd/C, the reaction conditions being 24 h and 60 °C. The complete reduction process of both aromatic rings required 12 h and 80 °C with Al powder in the presence of Pt/C.     

Sn‐mediated one‐pot four‐component allylation of aldimines

A convenient and facile method for the synthesis of homoallylic amines was disclosed. The one‐pot reaction of aldehydes, aromatic amines and allylic bromide with tin powder at room temperature could afford the homoallylic amines in good to excellent yield without any promoter or additive. The method is highly efficient and environmentally benign with low cost and concise manipulation. Copyright © 2014 John Wiley & Sons, Ltd.     

Direct Reductive Amination of Aldehydes and Ketones with 2,4-Ionene-Based Borohydride Exchange Resin as a Novel Polymer-Supported Reducing Agent

Direct reductive amination of aldehydes and ketones were accomplished efficiently using high-capacity, ionene-based, polymer-supported borohydride reagent in isopropyl alcohol at reflux under neutral conditions. The reagent is easily prepared by mixing aqueous solution of 2,4-ionene bromide with an alkaline solution of sodium borohydride at room temperature. The generality of reaction was established using both aliphatic and aromatic aldehydes, ketones, and amines.     

Efficient Synthesis of β‐Amino Alcohols Catalyzed by Niobium Pentachloride: Regioselective Ring Opening of Epoxides with Aromatic Amines

Epoxides undergo a rapid ring‐opening reaction with aromatic amines catalyzed by niobium pentachloride under mild reaction conditions. All the reactions were carried out at room temperature to afford the corresponding β‐amino alcohols in excellent yields and with high regioselectivity.     

无溶剂条件下N-磺酸琥珀酰亚胺催化乙酰化反应(英文)

A small amount of succinimide-N-sulfonic acid efficiently catalyzed the acetylation of a variety alcohols, phenols, thiols, amines and aldehydes with acetic anhydride at room temperature under solvent free conditions. This catalyst has the advantages of excellent yields and short reaction times and the reaction can be carried out on a large scale, which makes it potentially useful for industrial applications.     

Reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride under solvent free conditions

<正>A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH_4/silica chloride at room temperature,afforded excellent yield of the corresponding amines.     

One-pot three-component Mannich reaction catalyzed by iodine under solvent-free conditions

One-pot three-component Mannich reactions of ketones with aromatic aldehydes and aromatic amines are effectively catalyzed by molecular iodine at room temperature under solvent-free conditions to afford the corresponding β-amino carbonyl compounds with moderate to excellent yields. The method has the following advantages: no use of solvent, mild condition, high reaction speed and small quantity of catalyst.     

A Facile and Efficient Solid Supported,One‐Pot Synthesis of Functionalized Piperidine Derivatives Catalyzed by Amberlite IRA400‐Cl Resin/I2/KI via Multicomponent Reaction

A facile and efficient one‐pot, solid supported synthesis of functionalized piperidine derivatives catalyzed by Amberlite IRA400‐Cl resin/I₂/KI via a multicomponent reaction of various aldehydes, aromatic amines, and 1,3‐dicarbonyl compounds has been achieved. The reaction has been carried out in a one‐pot reaction and Amberlite resin as a solid supported catalyst at room temperature. Shorter reaction time, easy workup, yield, and mild reaction condition make the novel synthetic strategy both practical and attractive.     

利用Paal-Knorr反应在无催化剂和溶剂条件下合成吡咯衍生物

Paal-Knorr合成法是一个常见的吡咯合成方法。本文报道了无需使用任何催化剂和溶剂,在室温条件下多种胺(包括脂肪胺、芳香胺)和2,5-己二酮发生Paal-Knorr缩合反应,且合成的吡咯衍生物产率较高。这种合成方法具有反应条件温和、实验操作步骤简单以及产物容易分离等优点,具有一定的实用价值。     

One‐pot Synthesis of Highly Functionalized Tetrahydropyridines: A Camphoresulfonic Acid Catalyzed Multicomponent Reaction

A simple and straight forward solvent free method for the synthesis of a series of highly functionalized tetrahydropyridine derivatives has been achieved via multicomponent reaction of aromatic aldehydes, various amines, and β‐keto esters at room temperature using readily available (±)‐camphor‐10‐sulfonic acid as an organocatalyst. The current protocol offers an atom economic and environmentally benign method for the synthesis of the title compounds under solvent free conditions in good yields with high substrate scope and avoids column chromatographic purification.     

Reductive Amination of Aldehydes and Ketones to Their Corresponding Amines with NaBH4 in Micellar Media

A variety of aliphatic and aromatic aldehydes and ketones were efficiently reduced to their corresponding amines when treated with primary and secondary amines and NaBH₄ in micellar media at room temperature under neutral conditions.     

Reductive Amination of Aldehydes and Ketones to Their Corresponding Amines with NaBH<Subscript>4</Subscript> in Micellar Media

Summary. A variety of aliphatic and aromatic aldehydes and ketones were efficiently reduced to their corresponding amines when treated with primary and secondary amines and NaBH₄ in micellar media at room temperature under neutral conditions.     

Iron-promoted one-pot approach: Synthesis of isothiocyanates

Abstract

We have established a facile and versatile synthesis for the construction of isothiocyanates from their respective amines in the presence of an eco-friendly, inexpensive, easily available Iron catalyst under mild conditions. This reaction provides the target products through the formation of thiocarbamate salt as an intermediate. Both aromatic amines and aliphatic amines provided the respective target products in moderate to high yield under optimized reaction conditions. However, electron withdrawing substituents were difficult to give target product at room temperature, whereas, they obtained final products in good yield at moderate temperature. In addition, mechanistic studies were revealed that the synthetic route involved iron based subsequent reactions of addition and removal of sulfur.     

Reductive monoalkylation of aromatic and aliphatic nitro compounds and the corresponding amines with nitriles

[reaction: see text] A simple, selective, rapid, and efficient procedure for the synthesis of secondary amines from the reductive alkylation of either aliphatic or aromatic nitro compounds and the corresponding amines is reported. Ammonium formate is used as the hydrogen source and Pd/C as the hydrogen transfer catalyst. The reaction is carried out at room temperature. The rate differences for the preferential formation of secondary over tertiary products are due to both steric and electronic factors.     

Me3Ga-mediated alkynylation of aldehydes

The trimethylgallium reagent was found to promote the addition of phenylacetylene to various aromatic and aliphatic aldehydes. This reaction was efficiently carried out in anhydrous CH₂Cl₂ at room temperature under mild conditions and the corresponding propargylic alcohols were obtained in good to excellent yields up to 98%.     

Three‐Component Domino Reaction in PPG: An Easy Access to 4‐Thiazolidinone Derivatives

A simple, economical, and convenient synthesis of a new series of 4‐thiazolidinone derivatives using one‐pot three‐component condensation of aromatic amines, thioglycolic acid and aromatic aldehydes or cyclohexanone in polypropylene glycol (PPG), a recyclable and inexpensive solvent medium is reported. All the reactions are carried out at 110°C without using catalyst or additives. The products are obtained in good to excellent yields (60–97%) after easy workup and purification.     

温和条件下对甲基苯磺酸铝高效催化一锅法合成β-氨基酮衍生物

室温条件下,对甲基苯磺酸铝可有效催化芳香酮、芳香醛和芳香胺的Mannich反应,三组分"一锅法"合成了一系列β-氨基酮衍生物.考察了溶剂及反应条件对产率的影响.反应结束后,催化剂经简单相分离可回收并多次重复使用,催化活性无明显下降.产物结构经IR,~1H NMR,元素分析进行表征.     

A simple and efficient method for the synthesis of Erlenmeyer azlactones

We have recently developed a novel and efficient method for synthesising Erlenmeyer azlactones under mild and rapid conditions. The reaction is performed by reacting 2-phenyl-5-oxazolone with an aldehyde in dichloromethane using alumina as a catalyst. The materials react instantly at room temperature, negating the need for high temperatures and long reaction times. We have successfully used this method for both aliphatic, aromatic and heteroaromatic aldehydes, synthesising previously unmade Erlenmeyer azlactones in moderate to high yields.     

The one-pot process for the preparation of <Emphasis Type="Italic">N</Emphasis>-monoalkyl aromatic amines from nitroarene derivatives

A series of N-monoalkyl aromatic amines are synthesized in high yields from corresponding nitroarene derivatives, aldehydes, and ammonium formate in the presence of Pd/C as a catalyst through one-pot operations at room temperature. Both the conversion and selectivity of the process are above 80%. Optimum reaction conditions are investigated, and it is found that the optimum molar ratio of nitroarene derivatives to ammonium formate and the optimum weight ratio of nitroarene derivatives to Pd/C are 1/4 and 1/0.10, respectively. These experiments provide a novel access for N-monoalkyl aromatic amines with advantages of simplicity, high selectivity, and environmental benignity.