Metal-free graphene-based catalyst—Insight into the catalytic activity: A short review

AbstractAllylation of nucleophiles with highly reactive electrophiles like allyl halides can be conducted without metal catalysts. Less reactive electrophiles, such as allyl esters and carbonates, usually require a transition metal catalyst to facilitate the allylation. Herein, we report a unique transition-metal-free allylation strategy with allyl ether electrophiles. Reaction of a host of allyl ethers with 2-azaallyl anions delivers valuable homoallylic amine derivatives (up to 92%), which are significant in the pharmaceutical industry. Interestingly, no deprotonative isomerization or cyclization of the products were observed. The potential synthetic utility and ease of operation is demonstrated by a gram scale telescoped preparation of a homoallylic amine. In addition, mechanistic studies provide insight into these C(sp3)–C(sp3) bond-forming reactions.

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Exact analysis of the bending of wide beams by a modified elastica approach

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406211417753 ◽

2011 ◽

Vol 225 (11) ◽

pp. 2759-2764 ◽

Cited By ~ 8

Author(s):

L F Campanile ◽

R Jähne ◽

A Hasse

Keyword(s):

Finite Element ◽

Substantial Reduction ◽

Short Review ◽

Computational Effort ◽

Two Dimensional ◽

Finite Element Calculations ◽

Dimensional Finite Element ◽

Wide Beams ◽

Insight Into ◽

Selection Of

Classical beam models do not account for partial restraint of anticlastic bending and are therefore inherently inaccurate. This article proposes a modification of the exact Bernoulli–Euler equation which allows for an exact prediction of the beam's deflection without the need of two-dimensional finite element calculations. This approach offers a substantial reduction in the computational effort, especially when coupled with a fast-solving schema like the circle-arc method. Besides the description of the new method and its validation, this article offers an insight into the somewhat disregarded topic of anticlastic bending by a short review of the published theories and a selection of representative numerical results.

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Brief structural insight into the allosteric gating mechanism of BK (Slo1) channel

Canadian Journal of Physiology and Pharmacology ◽

10.1139/cjpp-2018-0516 ◽

2019 ◽

Vol 97 (6) ◽

pp. 498-502

Author(s):

János Almássy ◽

Péter P. Nánási

Keyword(s):

Quaternary Structure ◽

Short Review ◽

Bk Channel ◽

The Past ◽

Gating Model ◽

Cryo Electron Microscopy ◽

Gating Mechanism ◽

Electrophysiological Measurements ◽

Structural Insight ◽

Insight Into

The big conductance Ca2+-dependent K+ channel, also known as BK, MaxiK, Slo1, or KCa1.1, is a ligand- and voltage-gated K+ channel. Although structure-function studies of the past decades, involving mutagenesis and electrophysiological measurements, revealed fine details of the mechanism of BK channel gating, the exact molecular details remained unknown until the quaternary structure of the protein has been solved at a resolution of 3.5 Å using cryo-electron microscopy. In this short review, we are going to summarize these results and interpret the gating model of the BK channel in the light of the recent structural results.

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