title: Gold-Catalyzed Intermolecular Annulation to Access Heterocyclic Compounds
creator: Jin, Hongming
subject: ddc-540
subject: 540 Chemistry and allied sciences
description: In chapter 2, the gold-catalyzed C-H annulation of anthranil derivatives with alkynes offers a facile, flexible, and atom-economical one-step route to unprotected 7-acylindoles. An intermediate a-imino gold carbene, generated by an intermolecular reaction, promotes ortho-aryl C-H functionalization to afford the target products. The transformation proceeds with a broad range of substrates under mild conditions. Moreover, the obtained functionalized indole products represent a versatile platform for the construction of diverse indolyl frameworks.  In chapter 3, a gold-catalyzed cascade annulation of propargylic silyl ethers with anthranils proceeds through a sequential ring opening/1,2-H-shift/protodeauration/Mukaiyama aldol cyclization. This method offers a regiospecific and modular access to 2-aminoquinolines and other quinoline derivatives under mild conditions and with a broad functional-group tolerance. The conversion is possible on a gram scale, which underlines the synthetic practicability of this methodology. The versatility of the obtained scaffold has been demonstrated by useful postfunctionalization.  In chapter 4, gold and platinum-catalyzed counteranion-directed divergent [4+2] annulations have been described, enabling the convergent assembly of densely substituted quinoxaline and quinoxaline N-oxide from benzofurazans and ynamides. A broad scope of functional groups was well tolerated, delivering high regioselectivity. The quinoxaline N-oxides were suitable for the further C-H functionalization. Mechanism studies suggested the counteranion-tuned distinct cyclization pathways toward the corresponding product.  In chapter 5, the gold-catalyzed oxidative [2+2+1] annulation of two molecules of ynamide with 2, 3-quinoxaline N-oxide, enables the facile and convergent assembly of fully-substituted symmetric and unsymmetric furan frameworks. A wide range of functional groups is well compatible due to the mild condition. The strategy works also for the intramolecular macrocyclization of di-ynamides for the synthesis of macrocyclic furan derivatives.
date: 2019
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/23731/1/PhD%20Thesis-Hongming%20Jin.pdf
identifier: DOI:10.11588/heidok.00023731
identifier: urn:nbn:de:bsz:16-heidok-237313
identifier:   Jin, Hongming  (2019) Gold-Catalyzed Intermolecular Annulation to Access Heterocyclic Compounds.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/23731/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng