Open AccessCatalytic Enantio- and Diastereoselective Cyclopropanation of 2-Azadienes for the Synthesis of Aminocyclopropanes Bearing Quaternary Carbon Stereogenic Centers
Author(s) -
Xinxin Shao,
Steven J. Malcolmson
Publication year - 2019
Publication title -
organic letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.94
H-Index - 239
eISSN - 1523-7060
pISSN - 1523-7052
DOI - 10.1021/acs.orglett.9b02692
Subject(s) - stereocenter , cyclopropanation , diastereomer , chemistry , vicinal , diazo , stereochemistry , reagent , yield (engineering) , catalysis , quaternary carbon , carbon fibers , medicinal chemistry , enantioselective synthesis , organic chemistry , materials science , metallurgy , composite number , composite material
We report the catalytic enantio- and diastereoselective preparation of aminocyclopropanes by the cyclopropanation of terminal and ( Z )-internal 2-azadienes with donor/acceptor carbenes derived from α-diazoesters. The resulting cyclopropanes bear quaternary carbon stereogenic centers vicinal to the amino-substituted carbon and are formed as a single diastereomer in up to 99:1 er and 97% yield with 0.5 mol % of Rh 2 (DOSP) 4 and only 1.5 equiv of the diazo reagent. Transformations with internal azadienes afford cyclopropanes with three contiguous stereogenic centers.