Stronger Brønsted acids

Conformational diseases are caused by mutations altering the folding pathway or final conformation of a protein. Many conformational diseases are caused by mutations in secretory proteins and reach from metabolic diseases, e.g. diabetes, to developmental and neurological diseases, e.g. Alzheimer's disease. Expression of mutant proteins disrupts protein folding in the endoplasmic reticulum (ER), causes ER stress, and activates a signaling network called the unfolded protein response (UPR). The UPR increases the biosynthetic capacity of the secretory pathway through upregulation of ER chaperone and foldase expression. In addition, the UPR decreases the biosynthetic burden of the secretory pathway by downregulating expression of genes encoding secreted proteins. Here we review our current understanding of how an unfolded protein signal is generated, sensed, transmitted across the ER membrane, and how downstream events in this stress response are regulated. We propose a model in which the activity of UPR signaling pathways reflects the biosynthetic activity of the ER. We summarize data that shows that this information is integrated into control of cellular events, which were previously not considered to be under control of ER signaling pathways, e.g. execution of differentiation and starvation programs.

/pdf/er-stress-and-the-unfolded-protein-response-1uesskyggq.pdf

ER stress and the unfolded protein response.

Chiral nitrogen-containing compounds are widely distributed in nature and include many biologically important molecules (Chart 1). In these compounds, the nitrogen-containing units are known to play important roles for their bioactivities. For the synthesis of these chiral nitrogen-containing building blocks, use of imines as electrophiles is the most promising and convenient route.1 While many approaches using chiral imines or chiral nucleophiles have been reported,1 these diastereoselective reactions have some disadvantages. First, the procedures to introduce chiral auxiliaries to substrates and to remove them after the diastereoselective reactions are often tedious. Second, more than stoichiometric amounts of chiral sources are needed to obtain chiral compounds according to these reactions. On the other hand, catalytic enantioselective reactions provide the most efficient methods for the synthesis of chiral compounds,2 because large quantities of chiral compounds are expected to be prepared using small amounts of chiral sources. While much progress has been made recently in catalytic enantioselective reactions of aldehydes and ketones such as aldol,3 allylation,4 Diels-Alder,5 cyanation reactions,6 reduction,1b,2b etc., progress in catalytic enantioselective reactions of imines is rather slow. There are some difficulties in performing catalytic enantioselective reactions of imines. For example, in the cases of chiral Lewis acid promoted asymmetric Shū Kobayashi was born in 1959 in Tokyo, Japan. He studied chemistry at the University of Tokyo and received his Ph.D. in 1988 (Professor T. Mukaiyama). After spending 11 years at Science University of Tokyo (SUT), he moved to Graduate School of Pharmaceutical Sciences, University of Tokyo, in 1998. His research interests include development of new synthetic methods, development of novel catalysts (especially chiral catalysts), organic synthesis in water, solid-phase organic synthesis, total synthesis of biologically interesting compounds, and organometallic chemistry. He received the first Springer Award in Organometallic Chemistry in 1997.

https://chemistry.mdma.ch/hiveboard/picproxie_docs/000499541-cr980414z.pdf

Catalytic enantioselective addition to imines.

The nonaqueous rechargeable lithium–O2 battery containing an alkyl carbonate electrolyte discharges by formation of C3H6(OCO2Li)2, Li2CO3, HCO2Li, CH3CO2Li, CO2, and H2O at the cathode, due to electrolyte decomposition. Charging involves oxidation of C3H6(OCO2Li)2, Li2CO3, HCO2Li, CH3CO2Li accompanied by CO2 and H2O evolution. Mechanisms are proposed for the reactions on discharge and charge. The different pathways for discharge and charge are consistent with the widely observed voltage gap in Li–O2 cells. Oxidation of C3H6(OCO2Li)2 involves terminal carbonate groups leaving behind the OC3H6O moiety that reacts to form a thick gel on the Li anode. Li2CO3, HCO2Li, CH3CO2Li, and C3H6(OCO2Li)2 accumulate in the cathode on cycling correlating with capacity fading and cell failure. The latter is compounded by continuous consumption of the electrolyte on each discharge.

Reactions in the Rechargeable Lithium–O2 Battery with Alkyl Carbonate Electrolytes

π-Bonding and the Lone Pair Effect in Multiple Bonds between Heavier Main Group Elements

/pdf/kristallographische-computer-programme-fur-die-cdc-3300-maxej511am.pdf

Kristallographische Computer-Programme für die CDC-3300.

(Mesityl)2Ge(fluorenylidene)–Stabilization of a Ge–C Double Bond by Charge Transfer into an Aromatic System†

Die Monoalkylcarbonate M[O2COR] mit M = Li, Na, K, Rb, Cs, Tl und R = CH3, C2H5 wurden durch Umsetzung von CO2 mit den entsprechenden Alkoholaten dargestellt.



Die hergestellten Verbindungen wurden mit chemischen, rontgenographischen, differentialthermoanalytischen und massenspektrometrischen sowie mit IR-, UV- und 1H-NMR-spektroskopischen Methoden charakterisiert.



On Chalcogenolates. LXI. Studies on Hemiesters of Carbonic Acid. 1. Preparation and Properties of Monomethyl and Monoethyl Carbonates



Monoalkyl carbonates M[O2COR] with M = Li, Na, K, Rb, Cs, Tl, and R = CH3, C2H5 were formed by reaction of CO2 with alcoholates. The prepared compounds are investigated by different methods.

Martin Dräger

Papers

Kristallographische Computer-Programme für die CDC-3300.

(Mesityl)2Ge(fluorenylidene)–Stabilization of a Ge–C Double Bond by Charge Transfer into an Aromatic System†

Über Chalkogenolate. LXI. Untersuchungen über Halbester der Kohlensäure. 1. Darstellung und Eigenschaften von Monomethyl‐ und Monoäthylcarbonaten

Amino Acid Esters as Chiral Auxiliary Groups in Lewis Acid Catalyzed Reactions of Electron‐rich Siloxydienes with Imines

Über polygermane: XIV. Polygermane als nebenprodukte der Grignard-reaktion von PhMgBr mit GeCl4