Asymmetric Titanium-Catalyzed Cyclopropanation of Nitriles with Grignard Reagents

Julien Caillé (1) , Paul Setzer (1) , Fabien Boeda (1) , Morwenna Pearson-Long (1) , Philippe Bertus (1)

1 IMMM - Institut des Molécules et Matériaux du Mans

The titanium-catalyzed asymmetric cyclopropanation of cyanoesters­ with Grignard reagents was investigated for the first time. Particularly, the study of the efficiency of Taddol-based titanium complexes­ has shown that the prior preparation of Taddol titanium complexes was not required and a large panel of ligands was evaluated by using this approach. The spirocyclopropanelactams were obtained with good diastereoselectivity and with moderate enantioselectivities from the main diastereoisomer (up to 32%).

Mots clés: cyclopropanes; enantioselectivity; Grignard reagents; nitriles­; spiro compounds; titanium

Domaines: Chimie organique

Julien Caillé, Paul Setzer, Fabien Boeda, Morwenna Pearson-Long, Philippe Bertus. Asymmetric Titanium-Catalyzed Cyclopropanation of Nitriles with Grignard Reagents. SynOpen, 2018, 02 (01), pp.0041-0049. ⟨10.1055/s-0036-1591933⟩. ⟨hal-02132515⟩