Dimerik palladyum N-heterosiklik karben komplekslerinin sentezi, karakterizasyonu ve katalitik aktivitelerinin incelenmesi
Yükleniyor...
Dosyalar
Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Son yıllarda N-heterosiklik karbenler koordinasyon kimyasının ve organik dönüşüm reaksiyonlarında aranan ligant olmuştur. NHC'lerin doğal olarak güçlü σ-donör yeteneği, karbenlerin metal merkezlerine olağanüstü bağlanmasını ve metal ile karbenin yapmış olduğu bağın kararlılığını arttırır. Buna ek olarak, hem karben p-orbitaline π-geri bağlaması ile elektron transferi hem de karben p-orbitalinden π-verici olarak metale elektron transferi metal-ligand bağlanmasına sinerjik etki yaratır. N-hetrosiklik karbenlerin güçlü -donör ve zayıf -alıcı özelliklerinden ötürü fosfin ligantlarına göre metal merkezinde veya etrafında daha yüksek elektron yoğunluğu ile sterik hacim yaratır. NHC'lerin bu eşsiz özellikleri sayesinde M-NHC kompleksleri katalitik reaksiyonlarda yüksek kararlılıkla beraber oldukça iyi katalitik performans sergiler. Organik bileşiklerin değişik metal kompleksleri varlığında organik dönüşüm rekasiyonları ile sentezi endüstri ve akademi için oldukça önemlidir. C-H aktivasyon reaskiyonları son yıllarda endüstri ve özellikle farmasotik kimyada olmak üzere pek çok alanda kullanılan sübstitüye heteroaranlerin veya organik moleküllerin sentezinde oldukça önemlidir. Organometalik reaktifler oluşturulmadan direkt olarak hedeflenen sübstitüye heterosiklik bileşiklerin sentezi kullanılan katalizör ve ılımlı reaksiyon şartlarından ötürü oldukça ekonomik ve çevre dostu bir reaksiyondur. Pd-NHC komplekslerinin bu alandaki kullanımı her geçen gün arttığından bu alanda yeni nesil Pd-NHC komplekslerinin geliştirilmesi akademi ve sanai için oldukça önemlidir. Bu sebeplerden ötürü bu tez kapsamında simetrik ve asimetrik NHC öncülleri ve bu öncüllerin dimerik-köprülü palladyum komplekslerinin sentezi gerçekleştirilerek 2-izobütiltiyazolun aril bromürler ile direk C-H aktivasyonundaki katalitik aktiviteleri incelenmiştir. Bu tez çalışmasında bulunan sonuçlar 3 genel başlık altında sıralanabilir; 1)Benzimidazol temelli simetrik ve asimetrik NHC öncülleri (2a-f) sentezlenmiş ve yapısal karakterizasyonları değişik spektroskopik yöntemler ile yapılmıştır. 2)Benzimidazol temelli simetrik ve asimetrik NHC öncüllerinin dimerik köprülü palladyum kompleksleri (4a-f) sentezlenip yapıları uygun spektroskopik yöntemler ile aydınlatılmıştır. 3)Sentezlenen dimerik-köprülü Pd-NHC komplekslerinin (4a-f) 2-izobütiltiyazolün aril bromürler ile C-H aktivasyon reaksiyonlarındaki katalitik aktiviteleri incelenmiştir.
Recently, N-heterocyclic carbenes have become a sought-after ligand in coordination chemistry and organic conversion reactions. The inherently strong σ-donor ability of NHCs enhances the exceptional bonding of carbenes to metal centers and the stability of the metal-carbene bond. In addition, both electron transfer from the carbene p-orbital by π-backlinking and electron transfer from the carbene p-orbital to the metal as a π-donor create synergistic effects on metal-ligand bonding. Due to the strong -donor and weak -acceptor properties of N-hetrocyclic carbenes, it creates a steric volume with a higher electron density at or around the metal center than phosphine ligands. Thanks to these unique properties of NHCs, M-NHC complexes exhibit very good catalytic performance with high stability in catalytic reactions. The synthesis of organic compounds by organic transformation reactions in the presence of different metal complexes is very important for industry and academia. In recent years C-H activation reactions are very important in the synthesis of substituted heteroarenes or organic molecules used in many fields especially in pharmaceutical chemistry. The synthesis of directly targeted substituted heterocyclic compounds without the formation of organometallic reagents is a very economical and environmentally friendly synthetic procedure due to the catalyst used and the mild reaction conditions. Since the use of Pd-NHC complexes in this field is increasing day by day, the development of new generation Pd-NHC complexes in this field is very important for academia and industry. For these reasons, within the scope of this thesis, the catalytic activities of synthesized Pd-NHC complexes were investigated for 2-isobutylthiazole with aryl bromides in direct C-H activation. The results of this thesis can be listed under tree general headings; 1) Benzimidazole-based symmetric and asymmetric NHC precursors (2a-f) were synthesized and their structural characterizations were made by different spectroscopic methods. 2) Dimeric-bridged palladium complexes (4a-f) of benzimidazole-based symmetric and asymmetric NHC precursors were synthesized and their structures were elucidated by appropriate spectroscopic methods. 3) The catalytic activities of the synthesized dimeric-bridged Pd-NHC complexes (4a-f) were investigated for 2-isobutylthiazole with aryl bromides in C-H activation reactions.
Recently, N-heterocyclic carbenes have become a sought-after ligand in coordination chemistry and organic conversion reactions. The inherently strong σ-donor ability of NHCs enhances the exceptional bonding of carbenes to metal centers and the stability of the metal-carbene bond. In addition, both electron transfer from the carbene p-orbital by π-backlinking and electron transfer from the carbene p-orbital to the metal as a π-donor create synergistic effects on metal-ligand bonding. Due to the strong -donor and weak -acceptor properties of N-hetrocyclic carbenes, it creates a steric volume with a higher electron density at or around the metal center than phosphine ligands. Thanks to these unique properties of NHCs, M-NHC complexes exhibit very good catalytic performance with high stability in catalytic reactions. The synthesis of organic compounds by organic transformation reactions in the presence of different metal complexes is very important for industry and academia. In recent years C-H activation reactions are very important in the synthesis of substituted heteroarenes or organic molecules used in many fields especially in pharmaceutical chemistry. The synthesis of directly targeted substituted heterocyclic compounds without the formation of organometallic reagents is a very economical and environmentally friendly synthetic procedure due to the catalyst used and the mild reaction conditions. Since the use of Pd-NHC complexes in this field is increasing day by day, the development of new generation Pd-NHC complexes in this field is very important for academia and industry. For these reasons, within the scope of this thesis, the catalytic activities of synthesized Pd-NHC complexes were investigated for 2-isobutylthiazole with aryl bromides in direct C-H activation. The results of this thesis can be listed under tree general headings; 1) Benzimidazole-based symmetric and asymmetric NHC precursors (2a-f) were synthesized and their structural characterizations were made by different spectroscopic methods. 2) Dimeric-bridged palladium complexes (4a-f) of benzimidazole-based symmetric and asymmetric NHC precursors were synthesized and their structures were elucidated by appropriate spectroscopic methods. 3) The catalytic activities of the synthesized dimeric-bridged Pd-NHC complexes (4a-f) were investigated for 2-isobutylthiazole with aryl bromides in C-H activation reactions.
Açıklama
Anahtar Kelimeler
Kaynak
İnönü Üniversitesi Fen Bilimleri Enstitüsü
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
FIRAT, T. (2022). Dimerik palladyum N-heterosiklik karben komplekslerinin sentezi, karakterizasyonu ve katalitik aktivitelerinin incelenmesi.
