Premium
Asymmetric, Three‐Component, One‐Pot Synthesis of Spiropyrazolones and 2,5‐Chromenediones from Aldol Condensation/NHC‐Catalyzed Annulation Reactions
Author(s) -
Wang Lei,
Li Sun,
Chauhan Pankaj,
Hack Daniel,
Philipps Arne R.,
Puttreddy Rakesh,
Rissanen Kari,
Raabe Gerhard,
Enders Dieter
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201600515
Subject(s) - annulation , pyrazolones , aldol condensation , enantioselective synthesis , chemistry , aldol reaction , catalysis , organic chemistry , carbene , condensation , component (thermodynamics) , medicinal chemistry , physics , thermodynamics
A novel one‐pot, three‐component diastereo‐ and enantioselective synthesis of spiropyrazolones has been developed involving the aldol condensation of an enal to generate α,β‐unsaturated pyrazolones, which react with a second equivalent of enal through an N‐heterocyclic carbene (NHC)‐catalyzed [3+2] annulation. The desired spirocyclopentane pyrazolones are obtained in moderate to good yields and good to excellent stereoselectivities. Alternatively, starting from cyclic 1,3‐diketones, 2,5‐chromenediones are available through [2+4] annulation.