Bromine–Lithium Exchange on a gem -Dibromoalkene, Part 2: Comparative Performance of Flow Micromixers

Katia Pérez (1, 2) , Baptiste Picard (1) , Daniela Vuluga (2) , Fabrice Burel (2) , Rainier Hreiz (3) , Laurent Falk (3) , Jean-Marc Commenge (3) , Aiichiro Nagaki (4) , Jun-Ichi Yoshida (4, 5) , Isabelle Chataigner (1, 6) , Jacques Maddaluno (1) , Julien Legros (1)

1 COBRA - Chimie Organique et Bioorganique : Réactivité et Analyse
2 PBS - Polymères Biopolymères Surfaces
3 LRGP - Laboratoire Réactions et Génie des Procédés
4 Kyoto University
5 KOSEN - National Institute of Technology
6 LCT - Laboratoire de chimie théorique

The influence of the mixer shape on the stereoselectivity was measured for lithium–bromine exchange on a gem-dibromoalkene followed by proton trapping. Sixteen passive mixers with eight different angles (135, 120, and 105° (Y mixers); 90° (T mixer); 75, 60, 45, and 30° (W mixers)) and two internal diameters (500 and 250 μm) associated with a tubular microflow reactor having an internal diameter of 500 μm were used. The 45° W-shaped mixer with a smaller internal diameter gave the best selectivity for the monobrominated E product over a range of flow rates without the usual cryogenic conditions (20 °C). With methyl benzoylformate as the electrophile, the corresponding polyfunctionalized product was obtained in a space-time yield of 81 kg L–1 h–1.

Mots clés: microreactor shape; organolithium; carbenoid; stereoselectivity; microflow

Domaines: Chimie organique; Génie chimique

Katia Pérez, Baptiste Picard, Daniela Vuluga, Fabrice Burel, Rainier Hreiz, et al.. Bromine–Lithium Exchange on a gem -Dibromoalkene, Part 2: Comparative Performance of Flow Micromixers. Organic Process Research and Development, 2020, 24 (5), pp.787-791. ⟨10.1021/acs.oprd.0c00203⟩. ⟨hal-02996915⟩