Synthesis and reactivities of novel divalent group 14 elements species

• Main Author: Wang, Liliang
• Other Authors: Kinjo Rei
• Format: Theses and Dissertations
• Language: English
• Published: 2018
• Subjects: DRNTU::Science::Chemistry::Organic chemistry
• Online Access: http://hdl.handle.net/10356/73513
• Institution: Nanyang Technological University

In this thesis, we have first synthesized a cyclic (alkyl)(amino) germylene (CAAGe) which possesses the high-lying HOMO−1 and low-lying LUMO, which was supported by DFT calculations. The reactivities have been investigated subsequently. The reaction of CAAGe with S8 was first carried out, where led to the formation of the sulfido-bridged dimers as a mixture of two diastereomers involving Ge2S2 four-membered ring framework. But, when CAAGe was reacted with N2O, and only trans product was obtained. The treatment of CAAGe with TEMPO was also performed and led to the formation of a 1:2 adduct. CAAGe was also reacted with hydrosilanes in the presence of 20 mol% B(C6F5)3, where CAAGe was transformed into germylenes 10 and 11 via silyl group exchange. Lastly, the reactions of CAAGe with various gold(I), palladium(0) and palladium(II) complexes have been performed. The Au−Cl bond insertion products [ClGe−Au−NHC] were further reacted with various silver reagents to afford the corresponding [Ge−Au−NHC]•X complex. A new gold(I) complex featuring a pyrid-2-ylidene ligand was synthesized and fully characterized. It has been employed in hydroamination of alkynes with ammonia, which provided an efficient synthetic method for the construction of pyridine derivatives. It has also been utilized in the hydroimination of alkynes with imines, which indicated an apparent anti- Markovnikov regioselectivity to form 2-aza-1,3-dienes.