23876-45-1Relevant academic research and scientific papers
Br?nsted Acid Catalyzed [3+2]-Cycloaddition of 2-Vinylindoles with in Situ Generated 2-Methide-2H-indoles: Highly Enantioselective Synthesis of Pyrrolo[1,2-a]indoles
Bera, Kalisankar,Schneider, Christoph
, p. 7074 - 7078 (2016)
Pyrrolo[1,2-a]indoles are privileged structural elements of many natural products and pharmaceuticals. An efficient one-step process for their highly diastereo- and enantioselective synthesis, comprising a direct [3+2]-cycloaddition, has been developed. A chiral BINOL-derived phosphoric acid catalyzes the reaction of in situ-generated 2-methide-2H-indoles with 2-vinylindoles, furnishing the target products incorporating three contiguous stereogenic centers as single diastereoisomers and with excellent yields and enantioselectivities. In one step: A chiral Br?nsted acid catalyzed the highly enantioselective [3+2]-cycloaddition of in situ generated 2-methide-2H-indoles with 2-vinylindoles to directly furnish complex pyrrolo[1,2-a]indoles with three contiguous chiral centers. The products were obtained as single diastereoisomers and with yields up to 97 % and enantiomeric ratios up to 99.5:0.5.
