A palladium catalyst that converts terminal olefins to linear allylic acetates at lower catalyst loadings and faster reaction times than current systems is reported. This reaction can be conducted using benzoquinone as the oxidizing agent or catalytic amounts of copper and hydroquinone under one atmosphere of oxygen. Preliminary reactivity studies of pi-allylpalladium complexes under our reaction conditions do not provide results similar to those obtained in the catalytic reaction, which may suggest an alternative reaction pathway. The palladium catalyst is ligated by an aryloxyalkyl aryl sulfide, which is identified as a new ligand for homogeneous catalysis.

In this paper, we document observational support for the long-term weakening of the northwestern part of the Adriatic−Ionian thermohaline cell (AITHC), one of the 3 cells that drive the deep Mediterranean thermohaline circulation. The AITHC weakening is detected from longterm temperature, salinity and dissolved oxygen trends estimated from data measured between 1952 and 2010 along the Palagruža Sill, Adriatic Sea. We assumed that the weakening of the AITHC may be deduced from long-term changes in the dense water outflow characteristics across the sill, which are characterized by a strong decrease in dissolved oxygen content, slight warming and shallowing of the outflow and by lower advection of saline and warmer Levantine Intermediate Water (LIW) toward the northwestern Adriatic. The latter was deduced from the negative temperature trends and the lowest salinity trends estimated for the area of LIW inflow. Further weakening of the AITHC may have a noteworthy impact on deep aquatic systems and should therefore be monitored and assessed regularly.

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The rapid synthesis of 2,4-and 2,5-disubstituted oxazoles via metal-catalyzed cross-coupling reactions is reported. The 4-or 5-position of the corresponding 4-or 5-halogenated 2-butylthiooxazoles was successfully functionalized via SuzukiMiyaura, Sonogashira and Stille cross-coupling reactions. The 2-position of the 2-butylthiooxazoles obtained was further coupled to various organozinc reagents through palladium-or nickel-mediated cross-coupling reactions.

The lithium diisopropylamide mediated halogen dance reaction of 5-iodooxazoles to generate 4-iodooxazoles was studied. The mechanism of the reaction was investigated and compared to the reported mechanism for the halogen dance rearrangement of 5-bromooxazoles. Reaction conditions were optimized and yields of iodooxazole were improved to a synthetically useful level. The use of 2-(butylsulfanyl)-5-bromooxazole as an organic catalyst turned out to be the cornerstone for the success of this reaction.