A simple one-pot procedure for the direct conversion of alcohols into azides using TsIm

A facile and efficient method for one-pot conversion of alcohols into azides using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, alcohols are refluxed with a mixture of NaN₃, TsIm and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in DMF affording the corresponding alkyl azides in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°.     

A simple one-pot procedure for the direct conversion of alcohols into alkyl nitriles using TsIm

A convenient and efficient one-pot preparation of nitriles from alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, treatment of alcohols with a mixture of NaCN, TsIm and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in refluxing DMF furnishes the corresponding alkyl nitriles in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°.     

Efficient conversion of aromatic amines into azides: a one-pot synthesis of triazole linkages

[reaction: see text] An efficient and improved procedure for the preparation of aromatic azides and their application in the Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition ("click reaction") is described. The synthesis of aromatic azides from the corresponding amines is accomplished under mild conditions with tert-butyl nitrite and azidotrimethylsilane. 1,4-Disubstituted 1,2,3-triazoles were obtained in excellent yields from a variety of aromatic amines without the need for isolation of the azide intermediates.     

A novel stereoselective one-pot conversion of alcohols into alkyl halides mediated by N,N'-diisopropylcarbodiimide

Alcohols can be converted in high yields to the corresponding alkyl halides in a one-pot procedure via the corresponding O-alkylisourea; very short reaction times are possible when microwave irradiation is used.     

A new practical one-pot conversion of phenols to anilines

A novel one-pot synthesis of anilines from phenols was developed. Using this methodology, anilines are produced in good yield (86%) by a reaction of phenols with 2-bromo-2-methylpropionamide and NaOH in DMA via Smiles rearrangement. Phenols, which are substituted electron-withdrawing groups, are more reactive for Smiles rearrangement. Thiophenols are also converted to anilines. The process is a convenient, safe, and inexpensive method for large-scale preparation of anilines. [reaction: see text]     

Copper(II) acetate-catalyzed one-pot conversion of aldehydes into primary amides through a Beckmann-type rearrangement

Copper(II) acetate is a versatile catalyst for the direct transformation of any type of aldehydes into primary amides by stoichiometric reaction with hydroxylamine in water. The catalyst could be recovered 10 times without losing its activity, just by a simple organic layer extraction of the product. The catalyst and the protocol avoid the use of any type of expensive and difficult to handle organic ligand, as well as bases, showing excellent yields, under mild reaction conditions. The great purity of the crude product permits its purification by a simple recrystallization process. The whole protocol fulfils the principle of green chemistry and sustainability, minimizing the use of organic solvents and any type of wastes.     

Simple, facile and one-pot conversion of the Baylis-Hillman acetates into 3,5,6-trisubstituted-2-pyridones

A facile route for the synthesis of novel 3,5,6-trisubstituted-2-pyridones from the acetylated Baylis-Hillman esters with β-enamino esters or β-enamino nitriles in one pot with good yields is described.     

A one-pot conversion of ortho-alkynyl benzaldehydes into indolo[2,1-a]isoquinolines

The conversion of readily available 2-halobenzaldehydes into indolo[2,1-a]isoquinolines in two operations represents a very direct entry to this class of molecules.     

A novel one-pot conversion of aldehydes to trifluoromethylated bromoallylic alcohols

[reaction: see text]. One-pot conversion of aldehydes to trifluoromethylated bromoallylic alcohols in the presence of titanium isopropoxide and triphenylphosphine is described.     

Regioselective sulfonation of a secondary hydroxyl group of cyclodextrins

A new and convenient procedure has been developed for the regioselective tosylation of a C-2 hydroxyl group of cyclodextrins via cyclic tin intermediate.     

A theoretical study of the anomalous substituent effect of the hydroxyl group

A theoretical study by MINDO/3 and STO-3G SCF calculations has been used to examine the effect of a H-bonded water molecule on the ability of the hydroxyl group to stabilise a carbocation centre. Alkoxy groups are better stabilising groups in the gas phase, hydroxyl is more effective in protic solvents.     

Ultrasonic irradiation in one-pot synthesis of triethylaluminum etherate and its conversion into other organometallic compounds

A mixture of ethyl bromide, aluminum and magnesium powders was irradiated with ultrasound and ethylaluminum sesquibromide(I) formed at room temperature. As soon as diethyl ether was introduced into the reaction medium, ethylmagnesium bromide (II) was formed in situ and subsequently treated with I to give the etherate of triethylaluminum (III, TEA · OEt₂) in satisfactory yield (82%) and purity (98%). III, thus obtained, could react with triethyl borate or zinc chloride to give triethylborane (90%) and diethylzinc (82%) respectively.     

A novel method for the one-pot conversion of carboxylic acids to N,N-dimethylamides

A simple, efficient, and new method has been developed for the preparation of N,N-dimethylamides from carboxylic acids. As described below, treatment of a variety of aromatic carboxylic acids with N,N-dimethylsulfamoyl imidazole or N,N-dimethylsulfamoyl chloride in the presence of a mixture of methanesulfonic acid/phosphorus pentoxide (2:1, v/w) proceeded effectively to afford the corresponding N,N-dimethylamides in moderate to good yields. This method is easy, rapid, and good yielding for the synthesis of N,N-dimethylamides from carboxylic acids.     

Transformation of a hydroxyl into an acyl group on α-pyrone ring: a novel route to 3,4-diacylcoumarins

The transformation of a hydroxyl into an acyl group, a transformation which has been extensively investigated on the benzene nucleus of several substrates, is now applied successfully for the first time to a heterocyclic ring and specifically to the pyrone ring of coumarin to yield novel 3,4-diacylcoumarins in good yields. The reaction involves formation of a new C–C bond.     

Selective sulfonation of a secondary hydroxyl group of β-cyclodextrin

Tosylation of the secondary side of β-cyclodextrin, which has previously been incorrectly reported, can be achieved by tosyl transfer from 3-nitrophenyl toluenesulfonate to the C-2 hydroxyl of the cyclodextrin.     

The Loss of a hydroxyl group from the molecular ions of alkylnitrobenzenes

It is confirmed that the loss of HO˙ from the molecular ion of o-nitrotoluene involves exclusively a hydrogen from the methyl group. However, in higher homologues hydrogen atoms from non-benzylic sites are also implicated. With such compounds this fragmentation mode is shown not only by the ortho but, to a lesser extent, by the meta and para isomers as well. The proportion of the total ion current borne by the [M – 17]⁺ ion follows the order ortho > meta > para, which is attributed to substituent migration around the ring with a hydroxyl radical only being lost when the groups are on adjacent ring atoms. Other ions present in the spectra point to interaction between substituents to form a new heterocyclic ring.     

The conversion of halogen-containing polymers to the corresponding hydroxyl derivatives

The direct conversion of poly(epichlorohydrin), poly[3,3-bis(chloromethyl)oxetane], and poly-(vinyl chloroethyl ether) to the corresponding hydroxyl-containing polymers is described. The replacement of the halogen atom in several chlorine-containing polymeric esters by an acetyl group and the subsequent conversion of the latter derivatives to hydroxyl-containing polymers is also described.     

A m-benzyne to o-benzyne conversion through a 1,2-shift of a phenyl group

Pyrolysis of two differently labeled versions of 3-phenylphthalic anhydride shows that a m-benzyne can form the related o-benzyne through shift of a phenyl group. The highest energy point in the process is the transition structure for a reverse carbon-hydrogen insertion in an intermediate benzopentalene. With the minor addition of an intermediate alkyne formed through a Roger Brown rearrangement, the original mechanism for formation of acenaphthalene accommodates the labeling results.     

Mild oxidative one-pot allyl group cleavage

[reaction: see text]. A new one-pot method is described for the removal of O- and N-allyl protecting groups under oxidative conditions at near neutral pH. The allyl group undergoes hydroxylation and subsequent periodate scission of the vicinal diol, followed by repetition of this reaction sequence on the enolic form of the aldehyde intermediate.