One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor.

The Bohlmann-Rahtz pyridine synthesis and the Hantzsch dihydropyridine synthesis can be carried out in a microwave flow reactor or using a conductive heating flow platform for the continuous processing of material. In the Bohlmann-Rahtz reaction, the use of a Brønsted acid catalyst allows Michael addition and cyclodehydration to be carried out in a single step without isolation of intermediates to give the corresponding trisubstituted pyridine as a single regioisomer in good yield. Furthermore, 3-substituted propargyl aldehydes undergo Hantzsch dihydropyridine synthesis in preference to Bohlmann-Rahtz reaction in a very high yielding process that is readily transferred to continuous flow processing.

A deep tetranuclear metallo-cavitand with bis(aryl) palladium bridges.

A neutral metallo-cavitand based on cis bis-perhaloaryl Pd(II) bridges co-ordinated at the corners of a deep calix[4]arene. Both the metallo-cavitand and its inclusion complexes with other calix[4]arenes were investigated by means of (1)H and (19)F NMR experiments.

Continuous flow processing from microreactors to mesoscale: the Bohlmann-Rahtz cyclodehydration reaction.

The cyclodehydration of a number of Bohlmann-Rahtz aminodienones exemplifies the use of continuous flow processing to transfer operations from commercial microreactors and microwave batch reactors to mesoscale production using different technology platforms, including a microwave flow reactor.

A simple continuous flow microwave reactor.

A new simple procedure for microwave-assisted organic synthesis under continuous flow processing has been developed for use in a monomodal microwave synthesizer with direct temperature control using the instrument's in-built IR sensor. This design makes optimum use of the standing wave cavity to improve the energy efficiency of microwave-assisted flow reactions.