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Catalytic Asymmetric Synthesis of 8‐Oxabicyclooctanes by Intermolecular [5+2] Pyrylium Cycloadditions
Author(s) -
Witten Michael R.,
Jacobsen Eric N.
Publication year - 2014
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201402834
Subject(s) - intermolecular force , enantioselective synthesis , chemistry , thiourea , catalysis , stereoselectivity , octane , combinatorial chemistry , organocatalysis , stereochemistry , computational chemistry , molecule , organic chemistry
Highly enantioselective intermolecular [5+2] cycloadditions of pyrylium ion intermediates with electron‐rich alkenes are promoted by a dual catalyst system composed of an achiral thiourea and a chiral primary aminothiourea. The observed enantioselectivity is highly dependent on the substitution pattern of the 5π component, and the basis for this effect is analyzed using experimental and computational evidence. The resultant 8‐oxabicyclo[3.2.1]octane derivatives possess a scaffold common in natural products and medicinally active compounds and are also versatile chiral building blocks for further manipulations. Several stereoselective complexity‐generating transformations of the 8‐oxabicyclooctane products are presented.