Christophe Rochin

Formylation of aromation compounds in superacidic medium

Publisher Summary Chemists were always interested in introducing in one step a formylgroup into aromatic rings to obtain aldehydes. Several methods to obtain aromatic aldehydes are well-known. Formylation of aromatic rings can be obtained in HF-BF 3 medium using methyl formate, a stable and cheap material. High pressures are not required to make these formylations. Different functionalized aromatic rings are formylated in the required conditions with fair to good yields.

New synthesis of fluorobenzene and derivatives

Abstract Fluorobenzene and derivatives 1 can be easily and selectively prepared by fluorodecarboxylation from the corresponding haloformates 2 in a hydrogen fluoride media under gaseous conditions over a mineral catalyst (1). A large number of compounds were prepared and most of the case, the yields are high (fluorobenzene; fluorotoluenes; 1,4 difluorobenzene; halofluorobenzenes). The reactivity of substrates over different catalysts will be discussed.

Fluorodecarboxylation of arylchloroformate: A new access to fluoroaromatics

Summary The catalytic fluorodecarboxylation of arylchloroformate to fluorobenzene and analogues has been achieved with high yield in an anhydrous hydrogen fluoride vapor phase flow reactor. This methodology can be successfully applied to various derivates, the main limitation being the stability of substituents under the reaction conditions. The best catalysts are chromium and aluminium oxyfluoride. The reaction proceeds between 300 and 400°C and occurs in a short space of time. The catalytic activity decreases by coking but can be fully recovered by an oxydative treatment at high temperature. An ionic mechanism is proposed.