Direct experimental evidence for an enamine radical cation in SOMO catalysis

SOMO catalysis has lately obtained large interest as a new and powerful version of enantioselective organocatalysis which includes radical steps initiated by a one-electron oxidation. The intermediate enamine radical cation has been postulated, but has not been observed directly so far. This communication now reports the direct detection of this key intermediate.     

Als ein neues Reagens auf Phlorogluzin, Katechin und ihre Derivate

Ohne Zusammenfassung     

PHOTODYNAMIC ALTERATIONS OF THE CELL ENVELOPE OF PROTEUS MIRABILIS AND THEIR REPAIR

Abstract— Photodynamic treatment of Proteus mirabilis gives rise to changes in the cell envelope as can be detected by the behaviour of cells during lysis: lysis of cells proceeds more readily than that of untreated cells, measured by the liberation of labelled DNA. After photodynamic treatment the cell envelope is restored to the control levels. This repair process takes place within 5 min in broth as well as in buffer solutions.     

Organic transformations via metal silane reagents: syntheses of vinyl ethers from dimethyl ketals and (CO)5MnSi(CH3)3

The reaction of dimethyl ketals with (CO)₅MnSi(CH₃)₃ ($\text{1}$ at 50 °C in CH₃CN affords methyl enol ethers, generally in 75–95% yields.     

Long-term acid resistance and selectivity of NF membranes in very acidic conditions

The aim of the study was to test commercial and experimental NF membranes for their separation efficiency and acid resistance in a long-term filtration experiment. Several NF membranes (NF 270, Desal-5 DK, Desal KH, BPT-NF-1 and BPT-NF-2) were tested for their separation efficiency and stability when a solution containing 25 g/L CuSO₄ and 8 wt.% H₂SO₄ was continuously filtered at 40 °C for 2 months. Filtration experiments were carried out with a new five-cell flat-sheet laboratory apparatus. Commercial NF membranes showed good selectivity, retaining most of the copper sulphate and letting most of the sulphuric acid pass into the permeate. However, only the membranes designed to be acid resistant (Desal KH and BPT-NF-2) maintained their separation efficiency during the 2 months of separation. The Desal KH membrane gave better copper retention values (92–95%) than the BPT-NF-2 (60–88%), but the overall selectivity was best with the BPT-NF-2 membrane due to its good sulphuric acid permeation.