eprintid: 32582
rev_number: 15
eprint_status: archive
userid: 7134
dir: disk0/00/03/25/82
datestamp: 2023-01-11 13:23:53
lastmod: 2023-11-28 10:59:08
status_changed: 2023-02-01 12:17:38
type: doctoralThesis
metadata_visibility: show
creators_name: Liu, Yaowen
title: Gold-Catalyzed Regio- and Stereoselective 
Acyloxyalkynylations and Cycloadditions of Alkynes
subjects: ddc-540
divisions: i-120100
adv_faculty: af-12
abstract: In Chapter 2, multi-substituted alkenes are accessible by a gold-catalyzed 
acyloxyalkynylation of ynamides with ethynylbenziodoxolones (EBXs) in an 
atom-economic fashion. The EBX reagents act as bifunctional reactants providing both the nucleophilic carboxylate as well as the alkynyl entity. Overall this cascade involves the formation of an alkynyl Au(III) species, stereoselective C(sp)-C(sp2) bond formation and C-O coupling at the alkynyl position of the ynamides. The introduced method features mild conditions and wide substrate scope. A number of tetrasubstituted amide enol 2-iodobenzoates bearing diverse functionalities were prepared in good to excellent yield. DFT calculations exlain the observed regioselectivity. The synthetic potential of the sequence was further documented by a number of selected follow-up transformations.
In Chapter 3, Tetrasubstituted alkenes including the ester and ether group, is of great interest in chemistry and material sciences. A variety of tetrasubstituted enol ether 2-iodobenzoate derivatives were prepared in good yields at room temperature through a gold-catalyzed acyloxyalkynylation of ynol ethers with ethynylbenziodoxolones (EBXs), which act as bifunctional reactants in an atom-economic fashion. 
Furthermore, the mechanism involves an in situ formed alkynyl Au(III) species and a gram-scale reaction was efficiently conducted.
In Chapter 4, an efficient method for the construction of highly functionalized new spirooxindolocarbamates from a gold-catalyzed cycloaddition reaction of terminal alkyne and ynamides with isatin-derived ketimines is described. This protocol features easily accessible starting materials and good functional group compatibility enabling the introduction of various functionalized alkyne groups into cyclic carbamates. Gram-scale synthesis and proposed mechanism are also presented.
date: 2023
id_scheme: DOI
id_number: 10.11588/heidok.00032582
ppn_swb: 1871469899
own_urn: urn:nbn:de:bsz:16-heidok-325825
date_accepted: 2022-12-14
advisor: HASH(0x559e37e06468)
language: eng
bibsort: LIUYAOWENGOLDCATALY20221222
full_text_status: public
place_of_pub: Heidelberg
citation:   Liu, Yaowen  (2023) Gold-Catalyzed Regio- and Stereoselective Acyloxyalkynylations and Cycloadditions of Alkynes.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/32582/1/Doctoral%20Thesis_Yaowen%20Liu_.pdf