Palladyum N-heterosiklik karben komplekslerinin sentezi, karakterizasyonu ve katalitik aktivitelerinin incelenmesi
Küçük Resim Yok
Tarih
2024
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
İnönü Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
N-heterosiklik karben'ler (NHC) ile ilgili ilk çalışmalar 1960'larda Wanzlick ve Öfele'nin yapmış olduğu çalışmalar ile başlamıştır. 1990'larda, organik sentezde NHC'lerin uygulamaları ile ilgili çalışmalar rapor edilmiştir. Metallerin katalizör olarak kullanıldığı reaksiyonlarda ligand rollerinin yanı sıra, organo katalizör olarak karbenler, organik kimyada yeni bir bir araştırma alanı olarak ortaya çıkmıştır. NHC'ler organik reaksiyonlarda veya bileşenli reaksiyonlarda katalizör olarak veya birçok katalitik sistemde kullanılan komplekslerde anahtar ligand olarak kullanılmaktadır. NHC'lerin değişik geçiş metalli kompleksleri; metatez, C-C eşleşme tepkimeleri, hidroformilasyon, hidrosilasyon, aldehitlere boronik asit katılma tepkimesi, furan oluşumu, hidrojen transferi, metatez gibi birçok tepkimede katalizör olarak kullanılmaktadır. Katalizör olarak kullanılan komplekslerin sentezinde genellikle değişik oksidasyon basamağına sahip Pd, Cu, Co, Ru, Zn, Ag, Rh vb. geçiş metalleri tercih edilir. Bunun iki nedeni vardır. İlki metallerin değişik yu?kseltgenme basamaklarına sahip olmaları iken bir diğeri ise yu?kseltegenme basamakları arasındaki geçişlerde du?şu?k enerjiye gereksinim duymalarıdır. Bu tez kapsamında yeni NHC xv öncu?lleri sentezlenerek bu öncu?llerden değişik Palladyum N-heterosiklik karben komplekslerinin sentezi ve yapı analizi yapılarak bu komplekslerin katalitik aktivitelerinin C-H aktivasyonu ve Suzuki-Miyaura gibi organik dönu?şu?m reaksiyonlarındaki aktiviteleri incelenmiştir. Bu tez çalışması 4 ana başlık altında sıralanabilir; 1. İmidazol temelli simetrik NHC öncu?llerinin (2a-e) sentezi ve kimyasal yapılarının değişik spektroskopik yöntemlerle analizi, N H N + X R CH3CN , 80°C N N R R 2 K2CO3 X 2. İmidazol temelli simetrik NHC öncu?llerinin Pd-PEPPSI (3a-e) komplekslerinin sentezi ve kimyasal yapılarının farklı spektroskopik yöntemlerle analizi, N N R R + PdX2 + K2CO3 piridin, 80 °C X N N Pd R R N X X 3. Sentezlenen Pd-PEPPSI komplekslerinden çıkılarak NHC-PdX2-PPh3 (4a-e) komplekslerinin sentezi ve kimyasal yapılarının farklı spektroskopik yöntemlerle analizi, xvi N N + N N Pd N P Pd DCM R R R R X X X X P 4. Sentezlenen Pd-PEPPSI (3a-e) ve NHC-PdX2-PPh3 (4a-e) komplekslerinin C-H aktivasyon ve Suzuki-Miyaura eşleşme reaksiyonlarındaki katalitik aktivitelerinin incelenmesi. S N + + K.Piv DMA, 120°C S N R 3a-e, 4a-e R-Br R= 4-(CH3CO)Ph R= 4-(NO2)Ph R= 4-(CHO)Ph R= 4-(CN)Ph R= 4-(CH3)Ph R= 4-(OCH3)Ph R= 4-(CF3)Ph R= naphthalene R= 4-(CH3CO)Ph R= 4-(NO2)Ph R= 4-(CHO)Ph R= 4-(CN)Ph R= 4-(CH3)Ph R= 4-(OCH3)Ph R= 4-(CF3)Ph R= naphthalene
The first studies on N heterocyclic carbenes (NHCs) started in the 1960s with the studies of Wanzlick and Öfele. In the early 1990s, the applications of NHCs in organic synthesis were impressively demonstrated. Besides their excellent ligand role in metal based catalytic reactions, organocatalytic carbene catalysis has emerged as an extremely fruitful area of research in synthetic organic chemistry. NHCs are used as catalysts in organic reactions or compound reactions or as key ligands in complexes used in many catalytic systems. Different transition metal complexes of NHCs are used as catalysts in many reactions such as metathesis, C C coupling reactions (Heck and Suzuki coupling), hydroformylation, hydrosylation, boronic acid addition reaction to aldehydes, furan formation, hydr ogen transfer, metathesis. In the synthesis of complexes used as catalysts, commonly used transition metals such as Pd, Au, Rh, Ru, Ag are generally preferred to form metal complexes with different oxidation steps. There are two reasons for this. The first one is that the oxidation steps of metals are high and the second one is that they require low energy in the transitions between oxidation steps. Within the scope of this thesis, different xviii NHC precursors not available in the literature were synthesized and palladium Nheterocyclic carbene complexes were synthesized from these precursors and their catalytic activities were investigated in different organic conversion reactions (C-H activation and Suzuki). Four broad topics could be used to summarize the study's findings; 1. Imidazole based NHC salts (2a-e) were prepared and characterized by various spectroscopic techniques. N H N + X R CH3CN , 80°C N N R R 2 K2CO3 X 2. Pd-PEPPSI (3a-e) complexes of imidazole based symmetric NHC precursors were synthesized and characterized by various spectroscopic techniques. N N R R + PdX2 + K2CO3 piridin, 80 °C X N N Pd R R N X X 3. Pd-PPh3 (4a-e) complexes were synthesized from the synthesized Pd-PEPPSI complexes and characterized by various spectroscopic techniques. xix N N + N N Pd N P Pd DCM R R R R X X X X P 4. The catalytic activities of the synthesized Pd-PEPPSI and Pd-PPh3 complexes in CH activation and Suzuki reactions were investigated. S N + + K.Piv DMA, 120°C S N R 3a-e, 4a-e R-Br R= 4-(CH3CO)Ph R= 4-(NO2)Ph R= 4-(CHO)Ph R= 4-(CN)Ph R= 4-(CH3)Ph R= 4-(OCH3)Ph R= 4-(CF3)Ph R= naphthalene R= 4-(CH3CO)Ph R= 4-(NO2)Ph R= 4-(CHO)Ph R= 4-(CN)Ph R= 4-(CH3)Ph R= 4-(OCH3)Ph R= 4-(CF3)Ph R= naphthalene
The first studies on N heterocyclic carbenes (NHCs) started in the 1960s with the studies of Wanzlick and Öfele. In the early 1990s, the applications of NHCs in organic synthesis were impressively demonstrated. Besides their excellent ligand role in metal based catalytic reactions, organocatalytic carbene catalysis has emerged as an extremely fruitful area of research in synthetic organic chemistry. NHCs are used as catalysts in organic reactions or compound reactions or as key ligands in complexes used in many catalytic systems. Different transition metal complexes of NHCs are used as catalysts in many reactions such as metathesis, C C coupling reactions (Heck and Suzuki coupling), hydroformylation, hydrosylation, boronic acid addition reaction to aldehydes, furan formation, hydr ogen transfer, metathesis. In the synthesis of complexes used as catalysts, commonly used transition metals such as Pd, Au, Rh, Ru, Ag are generally preferred to form metal complexes with different oxidation steps. There are two reasons for this. The first one is that the oxidation steps of metals are high and the second one is that they require low energy in the transitions between oxidation steps. Within the scope of this thesis, different xviii NHC precursors not available in the literature were synthesized and palladium Nheterocyclic carbene complexes were synthesized from these precursors and their catalytic activities were investigated in different organic conversion reactions (C-H activation and Suzuki). Four broad topics could be used to summarize the study's findings; 1. Imidazole based NHC salts (2a-e) were prepared and characterized by various spectroscopic techniques. N H N + X R CH3CN , 80°C N N R R 2 K2CO3 X 2. Pd-PEPPSI (3a-e) complexes of imidazole based symmetric NHC precursors were synthesized and characterized by various spectroscopic techniques. N N R R + PdX2 + K2CO3 piridin, 80 °C X N N Pd R R N X X 3. Pd-PPh3 (4a-e) complexes were synthesized from the synthesized Pd-PEPPSI complexes and characterized by various spectroscopic techniques. xix N N + N N Pd N P Pd DCM R R R R X X X X P 4. The catalytic activities of the synthesized Pd-PEPPSI and Pd-PPh3 complexes in CH activation and Suzuki reactions were investigated. S N + + K.Piv DMA, 120°C S N R 3a-e, 4a-e R-Br R= 4-(CH3CO)Ph R= 4-(NO2)Ph R= 4-(CHO)Ph R= 4-(CN)Ph R= 4-(CH3)Ph R= 4-(OCH3)Ph R= 4-(CF3)Ph R= naphthalene R= 4-(CH3CO)Ph R= 4-(NO2)Ph R= 4-(CHO)Ph R= 4-(CN)Ph R= 4-(CH3)Ph R= 4-(OCH3)Ph R= 4-(CF3)Ph R= naphthalene
Açıklama
Anahtar Kelimeler
Kimya, Chemistry
