Obtaining quantitative agreement between theory and experiment for dissociative adsorption of hydrogen on and associative desorption of hydrogen from Cu(111) remains challenging. Particularly troubling is the fact that theory gives values for the high energy limit to the dissociative adsorption probability that is as much as two times larger than experiment. In the present work we approach this discrepancy in three ways. First, we carry out a new analysis of the raw experimental data for D2 associatively desorbing from Cu(111). We also perform new ab initio molecular dynamics (AIMD) calculations that include effects of surface atom motion. Finally, we simulate time-of-flight (TOF) spectra from the theoretical reaction probability curves and we directly compare them to the raw experimental data. The results show that the use of more flexible functional forms for fitting the raw TOF spectra gives fits that are in slightly better agreement with the raw data and in considerably better agreement with theory, even though the theoretical reaction probabilities still achieve higher values at high energies. The mean absolute error (MAE) for the energy E0 at which the reaction probability equals half the experimental saturation value is now lower than 1 kcal/mol, the limit that defines chemical accuracy, while a MAE of 1.5 kcal/mol was previously obtained. The new AIMD results are only slightly different from the previous static surface results and in slightly better agreement with experiment.

Ab initio molecular dynamics simulations with an adaptive biasing potential are carried out to study the reaction path in mononuclear Ru catalysts for water oxidation of the type [(Ar)Ru(X)(bpy)](+) with different aromatic ligands (Ar). The critical step of the O-O bond formation in the catalytic cycle starting from the [(Ar)Ru(O)(bpy)](2+) intermediate is analyzed in detail. It is shown that an explicit inclusion of the solvent environment is essential for a realistic description of the reaction path. Clear evidence is presented for a concerted reaction in which the O-O bond formation is quickly followed by a proton transfer leading to a Ru-OOH intermediate and a hydronium ion. An alternative path in which the approaching water first coordinates to the metal centre is also investigated, and it is found to induce a structural instability of the catalyst with the breaking of the aromatic ligand coordination bond.

Glucosylceramide synthase (GCS) is an important target for clinical drug development for the treatment of lysosomal storage disorders and a promising target for combating type 2 diabetes. Iminosugars are useful leads for the development of GCS inhibitors; however, the effective iminosugar type GCS inhibitors reported have some unwanted cross-reactivity toward other glyco-processing enzymes. In particular, iminosugar type GCS inhibitors often also inhibit to some extent human acid glucosylceramidase (GBA1) and the nonlysosomal glucosylceramidase (GBA2), the two enzymes known to process glucosylceramide. Of these, GBA1 itself is a potential drug target for the treatment of the lysosomal storage disorder, Gaucher disease, and selective GBA1 inhibitors are sought after as potential chemical chaperones. The physiological importance of GBA2 in glucosylceramide processing in relation to disease states is less clear, and here, selective inhibitors can be of use as chemical knockout entities. In this communication, we report our identification of a highly potent and selective N-alkylated L-ido-configured iminosugar. In particular, the selectivity of 27 for GCS over GBA1 is striking.

The O-allylation of bisphenol A (BPA) has been performed with the most selective catalysts for O-allylation of phenols reported previously. Both the cyclopentadienyl-ruthenium catalysts and the palladium-diphosphine catalysts are capable of selectively performing single and double O-allylation of BPA. An intriguing solvent effect is observed; the choice of the solvent is of key importance for both conversion and selectivity. The use of an excess of diallyl ether as allylating agent results in relatively high yields of the bisallyl ether of bisphenol A, while maintaining the high selectivity for O-allylation.

The scope of the dehydrative allylation reaction using allyl alcohol as allyl donor with [RuCp(PP)] + complexes as catalysts is explored. Aliphatic alcohols are successfully allylated with allyl alcohol or diallyl ether, obtaining high selectivity for the alkyl allyl ether. The reactivity of aliphatic alcohols is in the order of primary > secondary >> tertiary. The tertiary alcohol 1-adamantanol reacts extremely slowly in the absence of strong acid, but when HOTs is added, reasonable yields of 1-adamantyl allyl ether are obtained. The alkyl allyl ether is found to be the thermodynamically favored product over diallyl ether. Apart from alcohols, thiols and indole are also efficiently allylated, while aniline acts as a catalyst inhibitor. Allylation reactions with various substituted allylic alcohols give products with retention of the substitution pattern. It is proposed that a Ru(IV) σ -allyl species plays a key role in the mechanism of these allylation reactions.