Whilst hydrogen is a potentially clean fuel for energy storage and utilisation technologies, its conversion to electricity comes at a high energetic cost. This demands the use of rare and expensive precious metal electrocatalysts. Electrochemical-frustrated Lewis pairs offer a metal-free, CO tolerant pathway to the electrocatalysis of hydrogen oxidation. They function by combining the hydrogen-...

One or more methoxy groups on the benzylic carbon at the ortho-position of tricarbonylchromium-complexed aryl aldehydes (2, 3 or 4) permit chelation-controlled addition of nucleophiles to the carbonyl function in the presence of Lewis acids. In the absence of a Lewis acid additive, a complementary set of diastereomeric products are obtained.

The Lewis acid-mediated reactions of allene-ene compounds, derived from 3-methylcitronellal or dimethyl malonate, were carried out using various Lewis acids such as ethylaluminum dichloride, diethylaluminum chloride, titanium chloride, zinc chloride etherate, or boron trifluoride etherate, affording unexpectedly intramolecular [2+2]cycloaddition products under some particular reaction condition...

The strategic incorporation of internal Lewis acids onto urea scaffolds gives rise to a family of tunable hydrogen bond donor catalysts. The nature of the Lewis acid and associated ligands affects the urea polarization, acidity, and activity in reactions of nitrocyclopropane carboxylates and nitrodiazoesters.

The previously known dimeric arylantimony oxides (Ph3SbO)2 and [2,6-(Me2NCH2)2C6H3SbO]2 were disaggregated by the Lewis acid B(C6F5)3 giving rise to the formation of the Lewis pair complexes Ph3SbOB(C6F5)3 and 2,6-(Me2NCH2)2C6H3SbOB(C6F5)3 having short bipolar single Sb-O bonds.

The isomeric S-methyldihydropyrrins 9-Z and 9-E exhibit markedly different behavior in Pd(0)-catalyzed cross-coupling reactions. Thioimidates 9-Z are readily converted to imines 10-Z employing Pd(0)/AlkZnI. Under identical conditions 9-E are inert. Oxidative addition to Pd(0) requires activation by Zn or other Lewis acids, which is sterically unfavorable with 9-E. Analogous results were obtaine...

Background: It seems that there are similar associated diseases in psoriasis and Lewis (b) negative phenotypes such as diabetesmellitus, cardiovascular events, and metabolic syndrome. Therefore, we decided to evaluate the frequency of Lewis henotypes in patients with chronic plaque type psoriasis. A limited number of studies have been previously conducted in this regard.Methods: Fifty patients ...

ABSTRACT A Lewis acid–promoted nucleophilic addition of methallyltrimethylsilane to a chiral α-keto imide proceeded with stereoselectivity opposite that predicted from Soai's report. The difference in the structure imides between and our cases might have affected diastereofacial selectivity.

The oxidation of alcohols by KMnO(4) is greatly accelerated by various Lewis acids. Notably the rate is increased by 4 orders of magnitude in the presence of Ca(2+). The mechanisms of the oxidation of CH(3)OH and PhCH(OH)CH(3) by MnO(4)(-) and BF(3)·MnO(4)(-) have also been studied computationally by the DFT method.

A binary catalyst system for the enantioselective bromocycloetherification of 5-arylpentenols is described. The combination of an achiral Lewis base and a chiral Brønsted acid affords good enantioselectivities for the cyclization of Z configured 5-arylpentenols to form bromomethyltetrahydrofurans. The constitutional site selectivity is highly dependent upon the aromatic substituent and the conf...