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Request PDF | Solvent-free reactions of alkynes in ball mills: It is definitely more than mixing | This contribution presents two solvent-free reactions of terminal alkynes in ball mills: Pd ...
Very selective reactions have also been demonstrated inside ball mills, such as synthesising highly-strained cyclopropenes without the need for the usual blocking groups to prevent side reactions. Mack's lab ground alkynes and diazoacetates together in a vessel lined with either silver or copper foil – the heterogeneous catalyst.
Under solvent-free ball-milling conditions, the nucleophilic addition of terminal alkynes to carbonyl compounds takes place with the aid of potassium hydroxide base to afford propargylic alcohols 255 in moderate to high yields (Table 2.62).
Abstract: The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e., milling time, revolutions/min, size and milling ball number) have been optimized.
vated silicon nanoparticles is illustrated in Figure 1. A milling vial is loaded under inert atmosphere with non-spherical milli-meter-sized pieces of semiconductor-grade silicon and either an alkene or alkyne. Stainless steel milling balls are added to the vial, which is then sealed and placed in the high energy ball mill.
The present study illustrates the great potential of Sonogashira coupling using ball milling for the preparation of materials-oriented alkynes and for the discovery of …
A method for the Glaser coupling reaction of alkynes by using a vibration ball mill has been developed. The procedure avoids the use of ligands and solvents during the reaction. Aryl- and alkyl-substituted terminal alkynes undergo homocoupling if coground with KF-Al(2)O(3) and CuI as a milling auxiliary and catalyst. Furthermore, an alternative protocol has been developed …
Sonogashira coupling represents an indispensable tool for the preparation of organic materials that contain C(sp)–C(sp2) bonds. Improving the efficiency and generality of this methodology has long been an important research subject in materials science. Here, we show that a high-temperature ball-milling technique enables the highly efficient palladium-catalyzed …
Hydroamination Reactions of Alkynes with ortho‐Substituted Anilines in Ball Mills: Synthesis of Benzannulated N‐Heterocycles by a Cascade Reaction Maik Weiße Institute for Technical Chemistry and Environmental Chemistry, Friedrich Schiller University Jena, Lessingstrasse 12, 07743 Jena (Germany)
alkynes and azides in a planetary ball mill is reported. Synthetic chemistry carried out in ball mills has attracted. increasing attention within the last years, as indicated by the.
The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e., milling time, revolutions/min, size and milling ball number) have
The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e., milling time, revolutions/min, size and milling ball number) have been optimized. This …
A method for the Glaser coupling reaction of alkynes by using a vibration ball mill has been developed. The procedure avoids the use of ligands and solvents during the reaction. Aryl- and alkyl-substituted terminal alkynes undergo homocoupling if coground with KF-Al(2)O(3) and CuI as a milling auxiliary and catalyst.
An exemplary reaction is cyclopropenation of alkynes with diazoacetates carried out in ball mill using various materials for vial and balls. Silver foil was found to be a recyclable metal catalyst which does not loose activity and diastereoselectivity after several reaction cycles [ 29 ].
This contribution presents two solvent-free reactions of terminal alkynes in ball mills: Pd-catalyzed Sonogashira cross-coupling and Cu-catalyzed homo-coupling (Glaser reaction). The results are compared to other solvent-free reaction protocols, which have been published up to date for those types of reactions. Reactions are assessed on the basis of …
Hydroamination Reactions of Alkynes with ortho-Substituted Anilines in Ball Mills: Synthesis of Benzannulated N-Heterocycles by a Cascade Reaction Maik Weiße, Institute for Technical Chemistry and Environmental Chemistry, Friedrich Schiller University Jena, Lessingstrasse 12, 07743 Jena (Germany)
A method for the Glaser coupling reaction of alkynes by using a vibration ball mill has been developed. The procedure avoids the use of ligands and solvents during the reaction. Aryl- and alkyl-substituted terminal alkynes undergo homocoupling if coground with KF-Al(2)O(3) and CuI as a milling auxil …
hydroisoquinolines and alkynes can be accomplished under high-speed ball-milling conditions with copper balls (Scheme€9) [31]. Under these solvent-free reaction conditions, isoquino-lines 28 were formed more quickly than the in-solvent reac …
A method for the Glaser coupling reaction of alkynes by using a vibration ball mill has been developed. The procedure avoids the use of ligands and solvents during the reaction. Aryl- and alkyl-substituted terminal alkynes undergo homocoupling if coground with KF–Al 2 O 3 and CuI as a milling auxiliary and catalyst.
Mechanochemical Ruthenium-Catalyzed Hydroarylations of Alkynes under Ball-Milling Conditions. Hanchao Cheng, José G. Hernández, and Carsten Bolm * Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany. Org. Lett., 2017, 19 (23), pp 6284–6287.
The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e. milling time revolutions/min size and milling ball number) have been optimized.This new efficient facile and eco-friendly procedure has been tested on a number of different substrates and in all cases
ball-milling conditions proceed with excellent efficiency, thus providing practical access to materials-oriented aromatic alkynes in excellent yield with short reaction times (Figure 1c). In fact, using the mechanochemical Sonogashira coupling presented herein, a …
a milling material: agate, 20 min, 800rpm ≙ 13.3 Hz. b 20 min at 20 °C with maximal power input. c 60 in at 80 °C. d 30 min at 80 °C, maximal power input = 300 W.. The effective transfer of energy from the power socket into a product of interest has been proven for a number of examples. When different ball mills are compared with respect to their gross power …
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