Enantioselective Friedel-Crafts reaction of acylpyrroles with glyoxylates catalyzed by BINOL-Ti(IV) complexes.
We report the first efficient enantioselective Friedel-Crafts hydroxyalkylation of pyrroles having one electron-withdrawing group at the α, β or N-positions with alkyl glyoxylates catalyzed by readily available chiral BINOL-Ti(IV) complexes (1-5 mol %). The reaction regioselectively led to the desired pyrrole-hydroxyacetic acid derivatives with good yields (70-96%) and enantiomeric excesses up to 96%, and is applicable in multigram scale with low loading of the catalyst (1 mol %).
Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland.
Jakub
J
Majer
Piotr
P
Kwiatkowski
Janusz
J
Jurczak
D002384:Catalysis; D006038:Glyoxylates / Q000737:chemistry*; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D013237:Stereoisomerism; D014025:Titanium / Q000737:chemistry*
D006038:Glyoxylates; D009281:Naphthalenes; D011758:Pyrroles; C475744:S(-)2,2'-dihydroxy-1,1'-binaphthyl; D014025:Titanium