Microflow systems high temperatures

In this section, we discuss the cases where the use of microflow reactors allows us to conduct reactions under unconventional conditions, such as high temperatures, which significantly accelerate the rates of the reactions. In the macrobatch processes, however, the use of such reaction conditions may cause undesirable side reactions, such as the decomposition or subsequent reactions of products. Precise temperature control and short residence time, which minimize the consecutive side reactions, are responsible for successful reactions in microflow systems. 

Scheme 8.12 Synthesis of peptides using a microflow system at high temperatures...

Microflow systems serve as effective environments to perform various oxidation reactions using chemical reagents. The oxidation using dimethyl sulfoxide (DMSO), which is known as Moffatt-Swern type oxidation, is one of the most versatile and reliable methods for the oxidation of alcohols into carbonyl compounds in laboratory synthesis [1, 2]. However, it is well known that activation of DMSO leads to an inevitable side-reaction, Pummerer rearrangement, at temperatures above — 30°C (Scheme 7.1). Therefore, the reaction is usually carried out at low temperatures (—50 °C or below), where such a side-reaction is very slow [3, 4]. However, the requirement for such low temperatures causes severe limitations in the industrial use of this highly useful reaction. The use of microflow systems solves the problem. For example, the oxidation of cyclohexanol can be accomplished using a microflow... 

In the cation flow method an organic cation is generated continuously by low temperature electrolysis using an electrochemical microflow reactor. The cation thus generated is immediately allowed to react with a carbon nucleophile in the flow system. This method, in principle, enables the manipulation of highly reactive organic cations. 

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