Aryl ethers are important linking units in the structure of lignins and low rank coals that are thermally labile at 375°C. Mass transport limitations experienced in these cross-linked macromolecular solids can lead to alterations in thermochemical processing kinetics and product yields. The molecular level details of these alterations on reaction pathways are revealed through studies of model c...

A valuable pharmacophore, the 2-aminoimidazole moiety, can be accessed with a variety of substitution patterns through an addition-hydroamination-isomerization sequence (see scheme; R(1),R(4),R(5)=alkyl; R(3)=alkyl, aryl; R(2)=H, alkyl, aryl). The synthesis of the propargyl cyanamide precursors through a three-component coupling enables the preparation of this important heterocyclic core struct...

An effective phosphine-catalyzed method has been developed for the enantioselective addition of aryl thiols to the γ position of allenoates, thereby furnishing ready access to aryl alkyl sulfides in very good ee. An array of mechanistic data are consistent with addition of the chiral phosphine to the allenoate being the turnover-limiting step of the catalytic cycle. The optimized reaction condi...

The potential of selected microorganisms to O-dealkylate alkyl aryl ethers in a manner analogous to mammalian systems has been studied. A total of 45 fungi and actinomycetes were screened for their ability to O-demethylate 4-methoxybiphenyl. Of the 20 organisms found to actively metabolize this substrate, 5 were chosen for additional study. Incubation with a series of five homologous 4-alkoxybi...

Unlike their B-alkyl counterparts, brominated N-alkyl B-aryl 2,1-borazaronaphthalenes undergo a self-arylation reaction in the presence of a catalytic amount of palladium and base, in which the azaborine serves as both the electrophile and the nucleophile. The products of the self-arylation are air- and moisture-stable 2,1-borazaronaphthols, previously only observed in basic alcoholic solvents....

Ni-catalyzed ketone formation through mild reductive coupling of a diverse set of unactivated alkyl bromides and iodides with particularly aryl acid anhydrides was successfully developed using zinc as the terminal reductant. These conditions also allow direct coupling of alkyl iodides with aryl acids in the presence of Boc(2)O and MgCl(2).

Nano-silica supported titanium tetrachloride (TiCl4.SiO2) was prepared and used as an acid catalyst for the 14-aryl or alkyl-14H-dibenzo[a,,j]xanthenesreaction under solvent-free conditions. Compared to the classical 14-aryl or alkyl-14H-dibenzo[a,j]xanthenesreaction conditions, this method consistently has the advantage of excellent yie...

A methyl ketone, an aryl bromide, an electrophile, and ammonium chloride were combined in a four-component, three-step, and one-pot coupling procedure to furnish substituted isoquinolines in overall yields of up to 80%. This protocol utilizes the palladium catalyzed α-arylation reaction of an enolate, followed by in situ trapping with an electrophile, and aromatization with ammonium chloride. t...