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Efficient separation of minor actinides from spent nuclear fuel remains a formidable challenge. As part of ongoing efforts to identify effective ligands for separation of toxic radionuclides, a series of bis-1,2,4-triazines, three novel, have been prepared from [1,10]-phenanthroline-2,9-dicarbonitrile in two-telescoped steps without additives, complicated workups, prolonged reaction times, or additional purification.

Invited for this month's cover picture is the group of Professor Mark Peczuh at the University of Connecticut. The cover picture compares the rearrangement of a small molecule to the process of turning a stuffed animal inside out. The recycled, inside-out stuffed animals are both artistic and philosophically provocative. They capture the essence of the rearrangement reaction because the compounds themselves turn inside out over the course of the reaction, extending the diversity of products that can arise from simple starting materials. Small molecules often have functional groups with latent reactivity; under the appropriate conditions, those groups can react with other compounds (e.g., reagents) and also with other groups in the same molecule in an intramolecular reaction. The research team found that the epoxidation of some highly functionalized spiroketal compounds promoted rearrangements of their structures that turned them inside out. Some of the features of the products led them to use X-ray crystallography or a combination of computer-assisted structure elucidation, computation, and a new version of the 1,1-ADEQUATE NMR experiment to determine their structures. For more details, see the Communication on p. 577 ff.

A clean, mild and sustainable method for the functionalization of pyridines and their analogues is reported. A zinc-based Lewis acid is used to activate pyridine and its analogues towards nucleophilic aromatic substitution, conjugate addition, and cyclization reactions by binding to the nitrogen on the pyridine ring and activating the pyridine ring core towards further functionalization.

The transformation of electron-rich alcohols or secondary benzylic alcohols may be accompanied by the formation of the corresponding symmetrical ether which does not react with the substrate.

The use of a variety of copper salts as well as elemental copper and its oxides can be used to catalyze the dehydrogenation of a range of amine boranes with dimethylamine borane showing high levels of reactivity to the catalyst.

A mild acylation of N-alkylindoles is reported using sodium chlorodifluoroacetate (SCDA) to synthesize useful chlorodifluoroketones. Friedel–Crafts reactivity of carboxylate salts is unusual and is not observed in similar electron-deficient acetate salts such as sodium trifluoroacetate. Mechanistic experiments indicate that the characteristic ability of SCDA to generate difluorocarbene is responsible for the reaction pathway via self-activation to form the active ester.

Two novel synthetic strategies that allow rapid diversification of the sulfone moiety in sulfonylmethyl pyrimidines, a class of compounds with a wide range of biological activity, which are of interest in a wide variety of drug discovery programmes, are described.

A microwave-promoted and Ru-catalyzed procedure is developed to couple two different primary alcohols of type (I) and (II) to yield α,β-unsaturated aldehydes.

One-pot processes in which a single catalyst carries out several reactions are attractive, but typically promote the formation of by-products as well as the desired ones, and are not amenable to optimization of the individual transformations. Now, these issues have been overcome by separating the catalytic processes in time.

It has been 60 years since Eschenmoser and Frey disclosed the archetypal CC fragmentation reaction. New fragmentations and several variants of the original quickly followed. Many of these variations, which include the Beckmann, Grob, Wharton, Marshall, and Eschenmoser-Tanabe fragmentations, have been reviewed over the intervening years. A close examination of the origins of fragmentation has not been described. Recently, useful new methods have flourished, particularly fragmentations that give alkynes and allenes, and such reactions have been applied to a range of complex motifs and natural products. This Review traces the origins of fragmentation reactions and provides a summary of the methods, applications, and new insights of heterolytic CC fragmentation reactions advanced over the last 20 years.

Benzoxaborole derivatives are prepared from formylphenylboronic acid derivatives (I) utilizing Baylis-Hillman reaction [cf.

Bisisoxazoles are prepared in one step by the dropwise addition of aqueous potassium hydrogen carbonate to a mixture of dichloroglyoxime and terminal alkynes.

For the first time the tandem isomerization and nucleophilic aromatic substitution of allylic fluoro-substituted benzylic alcohols is described.

Acid chlorides can be activated by using simple iodide sources, e.g., KI or LiI, to undergo nucleophilic attack by a variety of relatively weak nucleophiles.

Zirconocene dichloride is found to efficiently catalyze acylation reaction with amides [cf.

Ene-type coupling reactions of alkynes with 1,3-diketones proceed at mild temperatures under air and in the presence of water.

Enantioenriched benzylic 2-methoxyethyl ethers react with methylmagnesium iodide to give enantioenriched 1,1-diarylethanes.

The title compounds (II) react with primary and secondary alcohols to yield the corresponding esters.

Over the last ten years there has been a huge increase in development and applications of organocatalysis in which the catalyst acts as a nucleophile. Amidines and guanidines are often only thought of as strong organic bases however, a number of small molecules containing basic functional groups have been shown to act as efficient nucleophilic catalysts. This tutorial review highlights the use of amidine, guanidine, and related isothiourea catalysts in organic synthesis, as well as the evidence for the nucleophilic nature of these catalysts. The most common application of these catalysts to date has been in acyl transfer reactions, although the application of these catalysts towards other reactions is an increasing area of interest. In this respect, amidine and guanidine derived catalysts have been shown to be effective in catalysing aldol reactions, Morita–Baylis–Hillman reactions, conjugate additions, carbonylations, methylations, silylations, and brominations.

Ketones (I) react with allyl acetate (II) to generate tertiary homoallylic alcohols (III) in the presence of a rhodium catalyst and bis(pinacolato)diboron.

Metal-free catalysis: A method for the transamidation of primary amides with primary or secondary amines provides access to secondary and tertiary amides, by utilizing catalytic quantities of hydroxylamine hydrochloride to activate the chemically robust primary amide group (see scheme). A mechanism of primary amide activation through a hydrogen-bonding complex is proposed.

Cyclization of o-aminobenzamide (I) with various benzylic and aliphatic alcohols proceeds smoothly under Ru-catalyzed hydrogen transfer conditions to afford quinazolines (III).

The direct coupling of unactivated carboxylic acids with amines can be performed in toluene 110 °C in the absence of catalyst. The use of simple zirconium catalysts at 5 mol% loading gave amide formation in as little as 4 h.

The reduction of a variety of organic substrates is achieved by Ru-catalyzed transfer hydrogenation with Me2NH·BH3.

Silver acetylides and organic azides react under copper(I) catalysis to afford 1,4-disubstituted 1,2,3-triazoles. Mechanistic studies implicate a process involving transmetallation to copper acetylides prior to cycloaddition. This work demonstrates that silver acetylides serve as suitable precursors for entry into copper-mediated coupling reactions. This methodology allows the incorporation of volatile and difficult-to-handle acetylenes into the triazole core.

The efficacy of the title agent is enhanced through its targeting to hypoxic regions of partial reperfusion.

This chapter describes the application of iridium complexes to catalytic hydrogen transfer reactions. Transfer hydrogenation reactions provide an alternative to direct hydrogenation for the reduction of a range of substrates. A hydrogen donor, typically an alcohol or formic acid, can be used as the source of hydrogen for the reduction of carbonyl compounds, imines, and alkenes. Heteroaromatic compounds and even carbon dioxide have also been reduced by transfer hydrogenation reactions. In the reverse process, the oxidation of alcohols to carbonyl compounds can be achieved by iridium-catalyzed hydrogen transfer reactions, where a ketone or alkene is used as a suitable hydrogen acceptor. The reversible nature of many hydrogen transfer processes has been exploited for the racemization of alcohols, where temporary removal of hydrogen generates an achiral ketone intermediate. In addition, there is a growing body of work where temporary removal of hydrogen provides an opportunity for using alcohols as alkylating agents. In this chemistry, an iridium catalyst “borrows” hydrogen from an alcohol to give an aldehyde or ketone intermediate, which can be transformed into either an imine or alkene under the reaction conditions. Return of the hydrogen from the catalyst provides methodology for the formation of amines or C–C bonds where the only by-product is typically water.

The process is efficient under thermal and microwave conditions in the presence of Cu(O-Ac)2.

Isoindolines are obtained with high cis-diastereochemistry by reaction of imines with organo-boron compounds.

Organocopper chemistry has long been known to be powerful synthetic methodology leading to the generation of C-C, C-O, C-N, C-S and C-X bonds. Advances in catalytic and stoichiometric organometallic reactions for the formation of C-C bonds from unfunctionalised arenes, e.g. by activation-functionalisation of a C-H bond, provides diverse and applicable reaction conditions for direct functionalisation. This review covers the background, applications and recent advances made in the area of aromatic C-X/C-H-bond couplings promoted by copper and copper/palladium mixed systems. The efficacy and scope of these reactions are discussed and the different methodologies are placed into context. Mechanistic considerations and evidence are highlighted at appropriate junctures in the review.

A wide range of secondary and tertiary amines as well as amides and sulfonamides is available.

The method allows the synthesis of various derivatives including ester (XIV) as the immediate precursor of the antiinflammatory drug tolmetin (XV).

The Ni-catalyzed coupling of aldoximes, used as substrates or generated in situ, with primary and secondary amines offers a novel synthesis of amides.

Amines have been formylated using aqueous formaldehyde or paraformaldehyde and the iridium catalyst [Cp∗IrI2]2. Paraformaldehyde acts as both a formylating agent and an oxidant.

Covering: up to the end of 2009 It is shown in this review that the application of an expert system for the purpose of computer-assisted structure elucidation allows the researcher to avoid the production of incorrect structural hypotheses, and also to evaluate the reliability of suggested structures. Many examples of structure revision using CASE methods are given.

The catalysis comprises oxidation by hydrogen transfer of the alcohols to the corresponding ketones and a CH activation/alkene insertion step.