A simple and efficient FeCl3-catalyzed direct alkylation of active methylene compounds with benzylic and allylic alcohols under mild conditions

A highly efficient FeCl₃-catalyzed alkylation of various active methylene compounds with various benzylic or allylic alcohols under mild conditions has been developed. The reaction was carried out in the presence of a catalytic amount of anhydrous FeCl₃ (10 mol %) under reflux in methylene chloride. High to excellent yields were obtained.     

An FeCl3-catalyzed highly C3-selective Friedel-Crafts alkylation of indoles with alcohols

The FeCl₃-catalyzed C3-selective Friedel-Crafts alkylation of indoles using allylic, benzylic and propargylic alcohols has been developed. The reaction was performed in the presence of a catalytic amount of inexpensive anhydrous FeCl₃ (10 mol %) in nitromethane under mild conditions. This method can also be used for the alkylation of pyrrole.     

An efficient and selective tosylation of alcohols with p-toluenesulfonic acid

Silica chloride has been found to be an efficient catalyst for facile tosylation of alcohols directly with p-toluenesulfonic acid in methylene chloride under reflux. The process is associated with selective tosylation of secondary alcohols over primary alcohols.     

PdCl2-catalyzed hydrosulfonamidation of homo allylic alcohols: an efficient synthesis of allylic sulfonamides

A new protocol for the palladium chloride-catalyzed direct hydrosulfonamidation of homoallylic alcohols with migration of the double bond is described. This method requires no preactivation of alcohols and the reaction is environmentally benign with water as the only by-product. Various homoallylic alcohols on hydrosulfonamidation with sulfonamides gave the corresponding products in good yields.     

Copper triflate/t-BuOOAc-catalyzed amidation of allylic and benzylic acetates with sulfonamides

A copper triflate/t-BuOOAc-catalyzed amidation of allylic and benzylic acetates has been developed which is suitable for the coupling of a wide variety of functionalized sulfonamide nucleophiles with acetate electrophiles. The methodology allows for the amidation of benzylic substrates which are not further activated by an additional adjacent alkene or alkyne, enabling simple allylic acetates and primary benzylic acetates to be used as reaction partners.     

FeCl3-catalyzed functionalization of monoterpenes via hydroalkylation of unactivated alkenes

Monoterpenes such as α-pinene, β-pinene, limonene and isolimonene undergo smooth hydroalkoxylation in the presence of 20 mol % of FeCl₃ under mild reaction conditions to produce a wide range of the corresponding ethers in excellent yields and with high selectivity.     

FeCl3-catalyzed propargylation of aromatic compounds with propargylic acetates

A new method for the synthesis of propargylated aromatic compounds is developed. The reaction was carried out at room temperature in the presence of a catalytic amount of FeCl₃ in acetonitrile, high product yields were obtained with excellent regioselectivity and the reaction proceeded smoothly without exclusion of moisture or air.     

Molybdenum(V) chloride-catalyzed amidation of secondary benzyl alcohols with sulfonamides and carbamates

A general and selective method for the direct amidation of secondary benzyl alcohols with both sulfonamides and carbamates is described. This method has been applied to a variety of substrates and the reaction proceeded smoothly at room temperature in the presence of 5 mol % molybdenum(V) chloride to give the desired products in good yields.     

FeCl3-catalyzed Ritter reaction. Synthesis of amides

A safe and inexpensive synthesis of amides, from benzylic alcohols and nitriles and from t-butyl acetate and nitriles, using a Ritter reaction catalyzed by FeCl₃·6H₂O is described.     

ZnCl2-catalyzed Ferrier reaction; synthesis of 2,3-unsaturated 1-O-glucopyranosides of allylic, benzylic and tertiary alcohols

Tertiary, allylic and benzylic alcohols react with 3,4,6-tri-O-acetyl-d-glucal in dichloromethane at 25°C in the presence of ZnCl₂ to afford the corresponding 2,3-unsaturated-1-O-glucopyranoside acetates in 65-91% yields, with selective formation of the α-anomer.     

An efficient method for chlorination of alcohols using PPh3/Cl3CCONH2

A new and convenient method for the chlorination of alcohols utilizing PPh₃/Cl₃CCONH₂ is addressed. Various alcohols could smoothly be converted into their corresponding alkyl chlorides in high yield under mild conditions with short reaction times. A mechanism is disclosed with the evidence of inversion of configuration of the analogous alkyl chloride derived from R-(−)-2-octanol.     

IrCl3 or FeCl3-catalyzed convenient synthesis of 3-hydroxyphthalates

IrCl₃·3H₂O or FeCl₃-catalyzed convenient synthesis of 3-hydroxyphthalates has been achieved by a Diels-Alder reaction of furans with dimethyl acetylenedicarboxylate, followed by ring-opening aromatization reaction of the Diels-Alder adducts, 7-oxabicyclo[2.2.1]hepta-2,5-diene derivatives. In addition, 7-azabicyclo[2.2.1]hepta-2,5-diene derivative, derived from N-Boc-pyrrole and dimethyl acetylenedicarboxylate, also converted into 3-aminophthalate derivative.     

FeCl3/PPh3-catalyzed Sonogashira coupling reaction of aryl iodides with terminal alkynes

Conditions for a FeCl₃/PPh₃-catalyzed and palladium-, copper-, amine free-Sonogashira coupling reaction of aryl halides with terminal alkynes are reported. The protocol was applicable to a wide variety of substituted aryl iodides and alkynes with different steric and electronic properties and gave excellent yields of the desired coupling products.     

An economic and efficient tetrahydrofuranylation of alcohols, imines and alkynes

The tetrahydrofuranyl radical, generated by heating tetrahydrofuran in the presence of air and allyl or benzyl chloride, becomes a useful tool in order to transform the hydroxyl functions into ethers, or the CN double bond into amine, or the C-C triple bond into vinyl derivatives. A radical mechanism is proposed followed by a nucleophilic substitution for the alcohol substrate and a radical addition for the iminic and the acetylenic reactants.     

Modifying bipolar membranes with palygorskite and FeCl3

To explore a more function-stable and energy-efficient bipolar membrane, palygorskite and FeCl₃ were added at the intermediate layer as water-splitting catalysts. As proven, the two materials have a synergetic effect on water splitting. Particularly, the bipolar membrane modified with 5 g dm⁻³ palygorskite and 0.005 mol dm⁻³ FeCl₃ can achieve a voltage drop of 0.68 V at 100 mA cm⁻² and loses only 14.7 μg of Fe after an electrodialysis operation at 100 mA cm⁻² for 660 min. Obviously, palygorskite can protect ferric ions from significant loss, which makes the membrane stable in the performance of water splitting. Nevertheless, how palygorskite immobilizes ferric ions is still under investigation.     

Sulfonylamidation of alkylbenzenes at benzylic position with p-toluenesulfonamide and 1,3-diiodo-5,5-dimethylhydantoin

Treatment of alkylbenzenes with p-toluenesulfonamide and 1,3-diiodo-5,5-dimethylhydantoin (DIH) in a small amount of carbon tetrachloride at 60 °C gave the corresponding α-p-toluenesulfonylamido)alkylbenzenes in good to moderate yields. The present reaction is a simple method for the α-sulfonylamidation of the benzylic position in alkylbenzenes.     

FeCl3: an efficient catalyst for reactions of electron-rich arenes with imines or aziridines

Iron(III) chloride was discovered highly effective as catalyst in the Friedel-Crafts reactions of electron-rich arenes with imines or aziridines. It was found that reactions of imines were highly substrate-dependent, which generated mono- or double-addition products, while arenes reacted with aziridines regioselectively leading to the formation of desired ring-opening products in 2 min with moderate to good yields.     

On the PdCl2-catalyzed synthesis of allylic azides and allylic sulfonamides from homoallylic alcohols

According to experimental and literature data, the one-pot formation of allylic azides or sulfonamides from catalytic amounts of PdCl₂, homoallylic alcohols and TMSN₃ or TsNH₂ occurs through CC migration followed by regioselective nucleophilic addition on the Pd^II-activated CC bond and β-OH elimination.     

First example of FeCl3-catalyzed alkylation of indoles with pinenes

Indoles undergo smooth alkylation with α- and β-pinenes in the presence of 20 mol % of anhydrous FeCl₃ under mild reaction conditions to produce a wide range of the corresponding 3-alkylated indoles in excellent yields with high trans-selectivity. This is the first example of alkylation of indoles with mono-terpenes.     

Efficient synthesis of indenes by FeCl3·6H2O-catalyzed intramolecular Friedel-Crafts reaction of aryl-substituted allylic alcohols

An efficient procedure for the synthesis of substituted indenes through the FeCl₃·6H₂O-catalyzed intramolecular Friedel-Crafts cyclization of aryl-substituted allylic alcohols has been developed. This method features the easily available starting materials, cheap catalyst, simple manipulation, and mild conditions.