87 research outputs found
Enhancing reductive cleavage of aromatic carboxamides
[GRAPHICS] A set of aromatic and especially heteroaromatic N-benzyl carboxamides, derived from naphthalene, pyridine, pyrazine, and quinoline, and the corresponding tert-butyl acylcarbamates have been synthesized and studied by cyclic voltammetry with respect to facilitated reduction. The latter undergo regiospecific cleavage of their C(O)-N bonds under very mild reductive conditions with formation of Boc-protected (benzyl)amine in most cases in nearly quantitative yields, Examples of preparative cleavage by controlled potential electrolysis, activated aluminum, and NaBH4 are given
Ultrafast laser micro-nano structuring of transparent materials with high aspect ratio
Ultrafast lasers are ideal tools to process transparent materials because
they spatially confine the deposition of laser energy within the material's
bulk via nonlinear photoionization processes. Nonlinear propagation and
filamentation were initially regarded as deleterious effects. But in the last
decade, they turned out to be benefits to control energy deposition over long
distances. These effects create very high aspect ratio structures which have
found a number of important applications, particularly for glass separation
with non-ablative techniques. This chapter reviews the developments of
in-volume ultrafast laser processing of transparent materials. We discuss the
basic physics of the processes, characterization means, filamentation of
Gaussian and Bessel beams and provide an overview of present applications
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