We present here the second complete genome of anaerobic ammonium oxidation (anammox) bacterium, Candidatus (Ca.) Brocadia pituitae, along with those of a nitrite oxidizer and two incomplete denitrifiers from the anammox bacterial community (ABC) metagenome. Although NO2− reduction to NO is considered to be the first step in anammox, Ca. B. pituitae lacks nitrite reductase genes (nirK and nirS) responsible for this reaction. Comparative genomics of Ca. B. pituitae with Ca. Kuenenia stuttgartiensis and six other anammox bacteria with nearly complete genomes revealed that their core genome structure contains 1,152 syntenic orthologues. But nitrite reductase genes were absent from the core, whereas two other Brocadia species possess nirK and these genes were horizontally acquired from multiple lineages. In contrast, at least five paralogous hydroxylamine oxidoreductase genes containing candidate ones (hao2 and hao3) encoding another nitrite reductase were observed in the core. Indeed, these two genes were also significantly expressed in Ca. B. pituitae as in other anammox bacteria. Because many nirS and nirK genes have been detected in the ABC metagenome, Ca. B. pituitae presumably utilises not only NO supplied by the ABC members but also NO and/or NH2OH by self-production for anammox metabolism.

Arylacetaldehydes were successfully synthesized by the anti-Markovnikov Wacker-type oxidation of vinylarenes using 1 atm O2 as a terminal oxidant under mild conditions. Electron-deficient alkenes, such as maleic anhydride and maleimides, were effective additives and would operate as ligands to stabilize the Pd(0) species during the reaction.

Hydrogenation of furfuryl alcohol and furfural over an activated carbon‐supported palladium catalyst was carried out and the effects of solvent and carbon dioxide on the activity and selectivity of the reactions were studied. For the hydrogenation of furfuryl alcohol and furfural, the addition of protic solvents led to a higher initial activity compared to that under neat conditions. Among the protic solvents, water caused the highest increase in the initial activities. When carbon dioxide was added to protic solvents, the initial activities increased further. For a system containing both water and carbon dioxide, the initial activity increased when the pressure of carbon dioxide introduced was increased up to 10 MPa, after which the activity remained almost constant. The results of the hydrogenation of furfural over the supported palladium catalyst showed that tetrahydrofurfural and furfuryl alcohol were the initial products; furfuryl alcohol was subsequently reduced to tetrahydrofurfuryl alcohol.

What prompted you to investigate this topic? We have recently found that the addition of electron-deficient cyclic alkenes, such as maleimide, accelerates ap alladium-cata-lyzed anti-Markovnikov Wacker-type oxidation of vinylarenest o arylacetaldehydes using O 2 .W ee xpected that this method could be applied to other reactions related to the anti-Markov-nikov Wacker-type oxidation, such as the one presented in this paper.The electron-deficient cyclic alkenesw ould operate as li-gands for palladium to accelerate the reactiona sw ella ss tabi-lize the in situ formed Pd 0 species, suppressing deactivation.

The development of an anti‐Markovnikov Wacker‐type oxidation for simple aliphatic alkenes is a significant challenge. Herein, a variety of aldehydes can be selectively obtained from various unbiased aliphatic terminal alkenes using PdCl2(MeCN)2/CuCl in the presence of p‐benzoquinone (BQ) under mild reaction conditions. Isomerization of the terminal alkene to the internal alkene was suppressed via slow addition of the starting material to the reaction mixture. In addition to the Pd catalyst, CuCl and BQ were essential in order to obtain the anti‐Markovnikov product with high selectivity. Terminal alkenes bearing a halogen substituent afforded their corresponding aldehydes with high anti‐Markovnikov selectivity. The halogen acts as a directing group in the reaction. DFT calculations indicate that a μ‐chloro Pd(II)−Cu(I) bimetallic species with BQ coordinated to Cu is the catalytically active species in the case of a terminal alkene without a directing group.