title: Tetrazolic acid functionalized dihydroindol: rational design of a highly selective cyclopropanation organocatalyst.
abstract: Herein we wish to report our development of an improved catalyst (S)-(-)-indoline-2-yl-1H-tetrazole (1) for the enantioselective organocatalyzed cyclopropanation of alpha,beta-unsaturated aldehydes with sulfur ylides. The new organocatalyst readily facilitates the enantioselective organocatalytic cyclopropanation, providing cyclized product in excellent diastereoselectivities ranging from 96% to 98% along with enantioselectivities exceeding 99% enantiomeric excess for all reacted alpha,beta-unsaturated aldehydes. The new catalyst provides the best results so far reported for intermolecular enantioselective organocatalyzed cyclopropanation.
authors.affiliation: Department of Biochemistry and Organic Chemistry, Uppsala University, SE-75123 Uppsala, Sweden.
authors.forename: Antti
authors.initials: A
authors.lastname: Hartikka
authors.forename: Per I
authors.initials: PI
authors.lastname: Arvidsson
mesh_terms: D002384:Catalysis; D003521:Cyclopropanes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D013777:Tetrazoles / Q000737:chemistry*
chemical_list: D003521:Cyclopropanes; D007211:Indoles; D013777:Tetrazoles