1379802-39-7Relevant academic research and scientific papers
A novel three-component [3+2] cycloannulation process for the rapid and highly stereoselective synthesis of pyrrolobenzoxazoles
Boomhoff, Michael,Schneider, Christoph
, p. 4185 - 4189 (2012)
A novel three-component, one-pot [3+2] cycloannulation process is reported that gives previously unknown tetrahydropyrrolo [2,1-b]benzoxazoles in good yields and generates four new σ bonds and two new stereogenic centers with excellent diastereoselectivity. The reaction of bissilyldienediolate with imine in aqueous CH3CN in the presence of various Lewis acids is examined. The relative configuration of tetrahydropyrrolo [2,1-b] benzoxazole show that benzoxazole forms a vaulted structure with both phenyl and ester substituents located on the convex face of the molecule, which most likely represents the thermodynamically favorable configuration. The three-component reaction of benzaldehyde, 2-aminophenol, and the nucleophile in CHCl3 in the presence of Sc(OTf)3 and the chiral N,N'-dioxide ligand with subsequent addition of tetra-n-butylammonium fluoride (TBAF) in CH 3CN/H2O gave product 3a in excellent yield and 81% enantiomeric excess.
