Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt
The work during my Ph.D period was devoted to develop the asymmetric cross coupling reactions in the presence of chiral guanidinium catalyst. A series of guanidine-derived organocatalysis was developed in Prof Tan Choon Hong’s lab, showing great efficiency in asymmetric transformations. The thes...
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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2018
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| Online Access: | http://hdl.handle.net/10356/74718 |
| _version_ | 1811689120748011520 |
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| author | Jiang, Huan |
| author2 | Tan Choon Hong |
| author_facet | Tan Choon Hong Jiang, Huan |
| author_sort | Jiang, Huan |
| collection | NTU |
| description | The work during my Ph.D period was devoted to develop the asymmetric
cross coupling reactions in the presence of chiral guanidinium catalyst. A series of
guanidine-derived organocatalysis was developed in Prof Tan Choon Hong’s lab,
showing great efficiency in asymmetric transformations.
The thesis presented here is divided into three chapters, mainly discussing the
exploration of enantioselective Csp3-Csp2 cross coupling to give optically active
products in the presence of metal complex and chiral guanidinium catalyst.
Chapter 1 of this thesis introduces the development of methodology for
asymmetric Csp3-Csp2 cross coupling catalyzed by transition metals, assorted by
types of electrophiles and nucleophiles employed in the reactions. Different
transition metal complexes and ligands are discussed and compared in terms of
capacity and disadvantage in asymmetric Csp3-Csp2 cross coupling. Proposal and
objectives are raised at the end of Chapter 1 to address the possibility of using
copper(I) salt and guanidinium for the reaction.
The following part in Chapter 2 is the detailed investigation of asymmetric
Csp3-Csp2 cross coupling catalyzed by copper(I) complex and guanidinium catalyst.
An array of cyclic allylic bromides were transformed to corresponding arylated or
vinylated products in good yields and high enantioselectivity. Mechanistic
exploration of the cross coupling process involves: (1) X-Ray crystal structure and
reactivity of guanidinium cuprate complex; (2) 63Cu NMR spectrum to observe the
interaction between copper(I) complex and other reagents; (3) “Hard” nucleophilic
attack pathway determined by change in the stereoselectivity of asymmetric allylic
arylation process.
Chapter 3 describes the extension of the developed methodology from cyclic
bromides to various prochiral acyclic bromides, giving a wider substrate scope of
SN2’ products in good enantioselectivity. The results illustrate the practicality of
our catalyst system in asymmetric allylic substitution with various substrates. |
| first_indexed | 2024-10-01T05:43:03Z |
| format | Thesis |
| id | ntu-10356/74718 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:43:03Z |
| publishDate | 2018 |
| record_format | dspace |
| spelling | ntu-10356/747182023-02-28T23:46:55Z Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt Jiang, Huan Tan Choon Hong School of Physical and Mathematical Sciences DRNTU::Science::Chemistry The work during my Ph.D period was devoted to develop the asymmetric cross coupling reactions in the presence of chiral guanidinium catalyst. A series of guanidine-derived organocatalysis was developed in Prof Tan Choon Hong’s lab, showing great efficiency in asymmetric transformations. The thesis presented here is divided into three chapters, mainly discussing the exploration of enantioselective Csp3-Csp2 cross coupling to give optically active products in the presence of metal complex and chiral guanidinium catalyst. Chapter 1 of this thesis introduces the development of methodology for asymmetric Csp3-Csp2 cross coupling catalyzed by transition metals, assorted by types of electrophiles and nucleophiles employed in the reactions. Different transition metal complexes and ligands are discussed and compared in terms of capacity and disadvantage in asymmetric Csp3-Csp2 cross coupling. Proposal and objectives are raised at the end of Chapter 1 to address the possibility of using copper(I) salt and guanidinium for the reaction. The following part in Chapter 2 is the detailed investigation of asymmetric Csp3-Csp2 cross coupling catalyzed by copper(I) complex and guanidinium catalyst. An array of cyclic allylic bromides were transformed to corresponding arylated or vinylated products in good yields and high enantioselectivity. Mechanistic exploration of the cross coupling process involves: (1) X-Ray crystal structure and reactivity of guanidinium cuprate complex; (2) 63Cu NMR spectrum to observe the interaction between copper(I) complex and other reagents; (3) “Hard” nucleophilic attack pathway determined by change in the stereoselectivity of asymmetric allylic arylation process. Chapter 3 describes the extension of the developed methodology from cyclic bromides to various prochiral acyclic bromides, giving a wider substrate scope of SN2’ products in good enantioselectivity. The results illustrate the practicality of our catalyst system in asymmetric allylic substitution with various substrates. Doctor of Philosophy (SPMS) 2018-05-23T05:14:47Z 2018-05-23T05:14:47Z 2018 Thesis Jiang, H. (2018). Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt. Doctoral thesis, Nanyang Technological University, Singapore. http://hdl.handle.net/10356/74718 10.32657/10356/74718 en 180 p. application/pdf |
| spellingShingle | DRNTU::Science::Chemistry Jiang, Huan Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt |
| title | Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt |
| title_full | Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt |
| title_fullStr | Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt |
| title_full_unstemmed | Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt |
| title_short | Enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper(I) salt |
| title_sort | enantioselective arylation and vinylation of allylic bromides catalyzed by guanidinium and copper i salt |
| topic | DRNTU::Science::Chemistry |
| url | http://hdl.handle.net/10356/74718 |
| work_keys_str_mv | AT jianghuan enantioselectivearylationandvinylationofallylicbromidescatalyzedbyguanidiniumandcopperisalt |