Title:
Ring-opening benzannulations of cyclopropenes, alkylidene cyclopropanes, and 2,3-dihydrofuran acetals: A complementary approach to benzo-fused (hetero)aromatics
Ring-opening benzannulations of cyclopropenes, alkylidene cyclopropanes, and 2,3-dihydrofuran acetals: A complementary approach to benzo-fused (hetero)aromatics
Authors
Aponte-Guzman, Joel
Authors
Advisors
France, Stefan
Collard, David M.
Fahrni, Christoph J.
Jones, Christopher W.
Oyelere, Adegboyega K.
Collard, David M.
Fahrni, Christoph J.
Jones, Christopher W.
Oyelere, Adegboyega K.
Advisors
Person
Person
Person
Person
Person
Associated Organizations
Series
Collections
Supplementary to
Permanent Link
Abstract
Over the past decades, functional group manipulation of aromatic precursors has been a common strategy to access new aromatic compounds. However, these classical methods, such as Friedel-Crafts alkylations and electrophilic/nucleophilic aromatic substitutions, have shown lack of regioselectivity besides the use of activators in excess amounts. To this end, numerous benzannulations to form benzo-fused substrates via Diels-Alder (DA), ring-closing metathesis (RCM), cycloaddition, and transition-metal-promoted processes have been reported. Appending a benzene ring directly onto a pre-existing ring is preferable to many classical methods due to the likely reduction of reaction steps and superior regiocontrol. However, many of these benzannulation reactions require air- and/or moisture- sensitive reaction conditions, a last oxidation step, or the use of highly functionalized precursors. Here we disclose three ‘complementary’ intramolecular ring-opening benzannulations to access a large array of functionalized (hetero)aromatic scaffolds utilizing cyclopropenes-3,3-dicarbonyls, alkylidene cyclopropanes-1,1-diesters, and 2,3-dihydrofuran O,O- and N,O- acetals as building blocks. More than 70 benzo-fused aromatic compounds were synthesized using this complementary approach with yields up to 98% and low catalyst loadings. With these benzannulation reactions in hand, we aim to open the synthetic door to a handful of bioactive natural products.
Sponsor
Date Issued
2016-05-27
Extent
Resource Type
Text
Resource Subtype
Dissertation