Development of catalysts for the stereoselective hydrogenation of α,β-unsaturated ketones

Iridium phosphinitoxazoline complexes were found to be new efficient catalysts for the asymmetric hydrogenation of arylated α,β-unsaturated ketones. Linear as well as cyclic substrates are hydrogenated with similar success, giving selectivities of up to 99.7% ee.     

An Unpredictable Reaction of <Emphasis Type="Italic">t</Emphasis>Bu<Subscript>2</Subscript>PHO·BCl<Subscript>3</Subscript> in the Presence of Water

Abstract  

When a benzene solution of tBu₂PHO·BCl₃ was exposed to air at room temperature, the phosphonium chloride [tBu₂PH₂]Cl was formed together with di-tert-butylphosphinic acid, tBu₂PO(OH). X-ray quality crystals of the hydrochloride [tBu₂PH₂]Cl·HCl were obtained from the reaction solution at room temperature. The hydrochloride [tBu₂PH₂]Cl·HCl crystallizes in the monoclinic space group P2₁ /m, a = 6.3012(7) ?, b = 6.8970(10) ?, c = 14.5011(15) ?, β = 99.376(9)°, V = 621.79(13) ?³, Z = 2, d _calcd = g cm⁻³ 1.165; R1 = 0.0510, wR2 = 0.1503 for 1,129 reflections with I > 2σ(I). The crystal was a non-merohedral twin with a contribution of 0.353(7) of the minor component. The structure is composed of discrete di-t-butylphosphonium cations and Cl anions. Both are located on a crystallographic mirror plane and are connected by P–H···Cl hydrogen bonds.     

Deformations and derived equivalences

Suppose and are block algebras of finite groups over a complete local commutative Noetherian ring whose residue field is a field of positive characteristic. We prove that a split-endomorphism two-sided tilting complex (as introduced by Rickard) for the derived categories of bounded complexes of finitely generated modules over , resp. , preserves the versal deformation rings of bounded complexes of finitely generated modules over , resp. .

     

How to approach membership of IAF/ILAC Arrangements: the peer evaluation system of IAF and ILAC for single accreditation bodies

Peer evaluation is used by the international accreditation organisations IAF and ILAC as a tool to harmonise the results of accreditation of conformity assessment bodies and as a control mechanism to ensure constantly competent services according to harmonized standards. Upon positive evaluation outcome, the accreditation body may join an Arrangement (MLA/MRA) between accreditation bodies, confirming systematic reliability and competence to the market. The objective of these Arrangements is that they will cover all accreditation bodies in all countries in the world, thus eliminating the need for suppliers of products or services to be certified in each country where they sell their products or services. This article is to aid single accreditation bodies wishing to sign these Arrangements in the future, and, furthermore, to communicate the procedure and the relevance of evaluation to the public in order to build up confidence in such Arrangements.