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The reaction of alkyl sulfinates with alkynyl(aryl)iodonium salts provides a facile access into otherwise difficult to obtain alkyl alkynyl sulfones and cyclic vinyl sulfones via 1,2-rearrangement or 1,5-CH insertion, respectively. In benzyl sulfinates, 1,5-CH insertion is not possible, so addition to the aromatic ring occurs, followed by ring expansion to generate novel bicyclic sulfones.

In the presence of sodium bromide and Oxone, a range of alkylbenzene derivatives are brominated and/or oxidized with up to four C-H bonds being functionalized.

Dimerization of silacyclobutanes has been achieved under palladium catalysis at room temperature. A previous report described the requirement for high temperature and a stoichiometric amount of palladium complex to effect this process.

Starting from N-allyl amides, a protocol for the preparation of isoxazoline substituted methanol derivatives is elaborated.

The study of the reactions of tertiary propargyl alcohols with sodium halides under oxidative conditions is presented. With sodium iodide, α-iodoenones were formed, however, with sodium bromide or chloride the α-haloenones were only formed in low yields under anhydrous conditions. Conversely, upon addition of water to the reaction mixtures, α,α-dibromoketones and α,α-dichloroketones were formed in good yields, but α,α-diiodoketones were not observed.

The synthesis of substituted dihydrooxazoles (II) and (IV) by a CuI-catalyzed cycloisomerization of terminal propargyl amides (I) is reported.

An oxidative rearrangement of tertiary alcohols mediated by m-CPBA is described that generates tetrasubstituted alkenes with a carboxylic acid substituent. The mechanism of the reaction is proposed to proceed through epoxidation of the alkyne to form an oxirene that undergoes a 1,2-aryl shift.

In situ generated hypoiodous acid initiates the rearrangement of tertiary propargylic alcohols to α-iodoenones under mild conditions and in good yields.

An unexpected rearrangement is observed when indole substrates bearing 2-hydroxymalonate residues are subjected to iodination conditions A).

Furans are five-membered aromatic heterocycles containing one oxygen atom that are commonly found in many important compounds such as natural products, pharmaceuticals and polymers. 1 Moreover, fur...

The reaction demonstrates a rare alkyne activation by an organocatalyst proceeding with good to excellent diastereoselectivity.

The corrosion and passivity of high purity iron in anhydrous dimethoxyethane with 0.5M LiAsF 6 have been studied by various electrochemical and surface analytical techniques. The motivations for this study were twofold; (i) to develop an understanding of the passivity of metals and alloys in anhydrous organic solutions at a fundamental level, and (ii) to apply what is learned to improve the performance and useful life of high energy density lithium batteries which employ organic solvents. The data show that iron displays a stable passive region with low current densities over a large range of anodic potentials. Several different passivation mechanisms have been identified in this stable region. Among these mechanisms is passivation by solvent chemisorption

Bromination of dehydroamino acid derivatives with NBS or Br 2 /2,6-lutidine yields (E)- or (Z)-β-bromo-dehydroamino acid derivatives selectively. Subsequent intramolecular Michael addition-elimination of an aziridine proceeds with complete retention of olefin geometry to provide the 1-azabicyclo[3.1.0]hex-2-ylidene ring system proposed for the azinomycin series of antitumor antibiotics

A twist in the tale: Recent reports have highlighted solutions to the problems encountered when drug candidates exist as slowly interconverting conformers or atropisomers (see scheme). This Minireview brings together the various strategies that have been adopted and proposes a general approach to handling an aspect of stereochemistry which has received little attention from drug regulatory agencies.

The xanthone natural product psorospermin was synthesized in 13 steps with an overall yield of 1.7%. This compound shows potent antineoplastic activity in a variety of cancer cell lines.

[reaction: see text] A stereocontrolled route to Nuphar alkaloids is described that employs a formal [3 + 3] cycloaddition strategy to assemble the piperidine nucleus. The addition of Pd-TMM complexes to aziridine 10 was found to be sluggish; however, the addition of a functionalized allyl Grignard reagent followed by a Mitsunobu condensation reaction provided 11 in high yield. The employment of this route in the formal synthesis of (-)-deoxynupharidine 1 is described.

This paper describes a novel route to functionalized piperidines via a formal [3+3] cycloaddition reaction of activated aziridines and palladium−trimethylenemethane (Pd-TMM) complexes. The cycloaddition reaction generally proceeds enantiospecifically with ring opening at the least hindered site of the aziridine. Therefore, readily available enantiomerically pure 2-substituted aziridines can be utilized to prepare enantiomerically pure 2-substituted piperidines in good to excellent yield. The N-substituent on the aziridine proved to be crucial to the success of this reaction with only 4-toluenesulfonyl (Ts) and 4-methoxybenzenesulfonyl (PMBS) aziridines permitting smooth cycloaddition to take place. Additionally, spirocyclic aziridines have been found to participate in the [3+3] cycloaddition reaction, whereas 2,3-disubstituted aziridines can be applied to provide fused bicyclic piperidines, albeit in low yield.

A review of work concerning the passivity of metals in organic solutions is presented. The apparent disagreement between results obtained by different investigators with respect to the presence or absence of passivity in anhydrous solutions and the effect of water additions is explained. The possible mechanisms for passivation in anhydrous organic solutions are reviewed and discussed in terms of the effect of acidity and water on the ability of each to provide protection to the metal surface. Recent results of the authors and other co-workers for the Fe/propylene carbonate system which are in support of the explanations developed are also included. The contrasting effect of water on the passivation behavior of metals in acidified and neutral solutions is examined and explained.