The contact length parameter as a geometric factor for user-centered design of pistol grip geometries of power tools.

In this study the geometric parameter of the contact length is introduced, which intends to combine force exertion and perceived handle comfort in an anthropometric length in order to determine an optimal handle circumference. To prove suitability of the approach, 31 subjects were determined and correlations to handle circumferences with the highest finger forces and highest rated comfort were investigated. For all fingers, medium correlations were found among the contact lengths and the circumferences determined with maximum force (p < 0.001, rindex = 0.348, rmiddle = 0.419, rring = 0.374 and rlittle = 0.337) with high accordance of median values. Weak to moderate correlations were found between circumferences with maximum comfort and the contact lengths (p < 0.001, rindex = 0.150, rmiddle = 0.265, rring = 0.174). Using finger-specific proportionality factors, the contact lengths can be determined directly from the hand lengths, which enables great benefits for user-centered design.

Dual role of Rh(III) catalyst enables regioselective halogenation of (electron-rich) heterocycles.

The Rh(III)-catalyzed selective bromination and iodination of electron-rich heterocycles is reported. Kinetic investigations show that Rh plays a dual role in the bromination, catalyzing the directed halogenation and preventing the inherent halogenation of these substrates. As a result, this method gives highly selective access to valuable halogenated heterocycles with regiochemistry complementary to those obtained using uncatalyzed approaches, which rely on the inherent reactivity of these classes of substrates. Furans, thiophenes, benzothiophenes, pyrazoles, quinolones, and chromones can be applied.

Rh(III)-catalyzed halogenation of vinylic C-H Bonds: rapid and general access to Z-halo acrylamides.

Herein, the regio- and stereoselective iodination, along with some examples for the bromination, of readily available acrylamides to access a variety of differently substituted Z-haloacrylic acid derivatives is reported. The reaction proceeds under mild conditions via a Rh(III)-catalyzed C-H-activation/halogenation mechanism and represents a rare example of a direct halogenation of electron-poor acrylic acid derivatives.

High-yielding, versatile, and practical [Rh(III)Cp*]-catalyzed ortho bromination and iodination of arenes.

We report a uniquely high-yielding, general, and practical ortho bromination and iodination reaction of different classes of aromatic compounds. This reaction occurs by Rh(III)-catalyzed C-H bond activation methodology and is therefore the first example of the application of this cationic catalyst for C-Br and C-I bond formation.