Ferrosen temelli C2-simetrik kiral fosfinit bileşikleri ve geçiş metal komplekslerinin sentezi, tanımlanması ve asimetrik transfer hidrojenasyon reaksiyonlarındaki katalitik etkinliklerinin araştırılması
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Tarih
2015
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Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Asimetrik kataliz enantiyomerik saflıktaki bileşiklere olan talebi karşılamak için hızla
gelişen bir çalışma alanıdır. Geçiş metallerine koordine olmak üzere yeni kiralligandlarındizaynı
ve sentezi asimetrik transferhidrojenasyon reaksiyonlarının gelişmesinde önemli bir rol
oynamaktadır. Asimetrik katalizde substratakiralite kazandırmak için kiral bir katalizör
gerekmektedir. Etkili bir asimetrik katalizör yüksek saflıkta olması istenen bir enantiyomeri iyi
bir optik ve katalitik verimle hızlı bir şekilde üretir. Özellikle, kiral alkoller vermek üzere
prokiral ketonların asimetrik transfer hidrojenasyonu son on yılda oldukça dikkat
çekmektedir.Kiralmetalosenligandları içeren bileşikler, özellikle kiralferrosenilligandları çok
yönlü uygulamalarından dolayı son yıllarda büyük önem kazanmış bir asimetrik katalizör
sınıfıdır. Ferrosenil grup polimerden biyoorganometalik kimyaya kadar birçok farklı alanda
yaygın bir şekilde incelenmiştir. Uygulama alanları arasında kiralligandlar kullanılarak
gerçekleştirilen asimetrik sentez çalışmaları dikkat çekmektedir.Ferrosen temelli kiralfosfinler
ve aminofosfinler aralarında hidrojenasyon, hidrosililasyon, çapraz eşleşme reaksiyonları ve
aldolkondensasyonununda olduğu birçok enantiyoseçici reaksiyonda aktif katalizör olarak görev
alan geçiş metal kompleksleri oluştururlar. Bazı ferrosenilaminoalkol, fosfin, aminofosfin ve
VIII
iminodifosfinler ketonların rutenyum(II) katalizli transfer hidrojenasyonlarındaligand olarak
başarıyla kullanıldıkları halde, ferrosenilfosfinitlerin bu reaksiyonlardaki katalitik aktiviteleriyle
ilgili sınırlı sayıda çalışma bulunmaktadır.Bu çalışmada, değişik alkilveyaarilgrupları içeren
kiral bileşiklerden kiralC2-simetrik ferrosenilaminoalkoller hazırlanmıştır.
Ferrosenilaminoalkollerinmonoklorodifenilfosfin ile reaksiyonlarından yeni C2 simetrik ferrosen
temelli bisfosfinit bileşikler sentezlenmiştir. Bu FosfinitlerinRu(II), Rh(I) ve Ir(III) metal
kompleksleri sentezlenip tanımlanmaları yapılmıştır. Son olarak bu geçiş metal komplekslerinin
elektron çekici-verici veya sterik engelli gruplar içeren aril/alkil ve alkil/alkil ketonların transfer
hidrojenasyon reaksiyonlarında katalizör olarak kullanılabilirlikleri incelenmiştir.
Anahtar Kelimeler: Ferrosen, Fosfinit, C2-Simetrik, Kataliz, Asimetrik Transfer
Hidrojenasyon
Asymmetric catalysis has become a growing field of study as the demand for more enantiomerically pure compounds arises. The design and synthesis of new chiral ligands for transition metals have played a significant role in the development of the asymmetric transfer hydrogenation reactions. Asymmetric catalysis requires that a chiral catalyst be used in order to transfer its chirality to the substrat. An effective asymmetric catalyst will quickly produce a chiral product in good yield with high enantiomeric purity of the desired enantiomer. In particular, asymmetric transfer hydrogenation of prochiralketones to provide chiral alcohols has received a great deal of attention in the last decade or so.Compounds containing chiral metallocene ligands, in particular chiral ferrocenyl ligands, are one class of asymmetric catalysts that has received significant attention in recent years due to the versatility of these catalysts in a variety of applications. The ferrocenyl group has been widely explored in different areas, from polymers to bioorganometallic chemistry. Among several applications, the use of ferrocenebased chiral ligands in asymmetric synthesis is the most prominent.Ferrocene-based chiral phosphines and aminophosphines form transition metal complexes which have already been X identified as active catalysts in a variety of enantioselective reactions including hydrogenation, hydrosilylation, cross-coupling reactions and aldol condensation. Although some ferrocenylaminoalcohols, phosphines, aminophosphines and iminodiphosphines have been employed successfully as ligands in ruthenium(II)-promoted transfer hydrogenation of ketones, a screening of catalytic activity of ferrocenylphosphinites in this reaction is limited.In the present work, the ciralC2-symmetric ferrocenylaminoalcoholswere prepared from the chiral compounds having different aril and alkyl groups, The new C2-symmetric bisphosphinite compounds were synthesized by the reaction of C2-symmetric ferrocenylaminoalcohols with Ph2PCl. Ru(II), Rh(I) and Ir(III) metal complexes of preparedphosphiniteligandswere synthesized and characterized. Finally, use of these transition metal complexes as catalysts in asymmetric transfer hydrogenation reactions of aryl/alkyl and alkyl/alkyl ketones were investigated. KeyWords: Ferrocene, Phosphinite, C2Symmetric, Catalysis, Asymmetric Transfer Hydrogenation.
Asymmetric catalysis has become a growing field of study as the demand for more enantiomerically pure compounds arises. The design and synthesis of new chiral ligands for transition metals have played a significant role in the development of the asymmetric transfer hydrogenation reactions. Asymmetric catalysis requires that a chiral catalyst be used in order to transfer its chirality to the substrat. An effective asymmetric catalyst will quickly produce a chiral product in good yield with high enantiomeric purity of the desired enantiomer. In particular, asymmetric transfer hydrogenation of prochiralketones to provide chiral alcohols has received a great deal of attention in the last decade or so.Compounds containing chiral metallocene ligands, in particular chiral ferrocenyl ligands, are one class of asymmetric catalysts that has received significant attention in recent years due to the versatility of these catalysts in a variety of applications. The ferrocenyl group has been widely explored in different areas, from polymers to bioorganometallic chemistry. Among several applications, the use of ferrocenebased chiral ligands in asymmetric synthesis is the most prominent.Ferrocene-based chiral phosphines and aminophosphines form transition metal complexes which have already been X identified as active catalysts in a variety of enantioselective reactions including hydrogenation, hydrosilylation, cross-coupling reactions and aldol condensation. Although some ferrocenylaminoalcohols, phosphines, aminophosphines and iminodiphosphines have been employed successfully as ligands in ruthenium(II)-promoted transfer hydrogenation of ketones, a screening of catalytic activity of ferrocenylphosphinites in this reaction is limited.In the present work, the ciralC2-symmetric ferrocenylaminoalcoholswere prepared from the chiral compounds having different aril and alkyl groups, The new C2-symmetric bisphosphinite compounds were synthesized by the reaction of C2-symmetric ferrocenylaminoalcohols with Ph2PCl. Ru(II), Rh(I) and Ir(III) metal complexes of preparedphosphiniteligandswere synthesized and characterized. Finally, use of these transition metal complexes as catalysts in asymmetric transfer hydrogenation reactions of aryl/alkyl and alkyl/alkyl ketones were investigated. KeyWords: Ferrocene, Phosphinite, C2Symmetric, Catalysis, Asymmetric Transfer Hydrogenation.
Açıklama
Anahtar Kelimeler
Ferrosen, Ferrocene, Fosfinit, Phosphinite, C2-Simetrik, C2Symmetric, Kataliz, Catalysis, Asimetrik Transfer Hidrojenasyon, Asymmetric Transfer Hydrogenation
