Primjena posredne indukcije kiralnosti u asimetričnoj katalizi

doctoral thesis

• Title: Primjena posredne indukcije kiralnosti u asimetričnoj katalizi : enantioselektivno hidrogeniranje komplesima rodija s biokonjugatima trifenilfosfina i kiralnih aminokiselina
• Title (english): Application of backdoor induction of chirality in asymmetric catalysis : enantioselective hydrogenation with rhodium complexes of triphenylphosphine amino acid bioconjugates
• Author: Zoran Kokan; MBZ: 326816
• Mentor: Srećko Kirin (mentor)
• Committee member: Ines Primožič (predsjednik povjerenstva)
• Committee member: Srećko Kirin (član povjerenstva)
• Committee member: Ivo Piantanida (član povjerenstva); MBZ: 202026
• Committee member: Marina Cindrić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2014-06-27, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

U okviru ovog rada pripravljena su ukupno 73 nova liganda derivata trifenilfosfina s aminokiselinama, kraćim peptidima i/ili aminima. Ligandi su podijeljeni u tri skupine (A, B i C) obzirom na supstituciju fenilnog prstena fosfina i dentatnost, a njihovi in situ pripravljeni kompleksi s Rh(I) ispitani su kao homogeni katalizatori u reakcijama enantioselektivnog hidrogeniranja dvaju modelnih supstrata, metil-2-acetamidoprop-2-enoata (S1) i metil-(Z)-2-acetamido-3-fenilprop-2-enoata (S2). Kiralna informacija aminokiselina udaljena je od prokiralnog metala, a prenosi se "posrednom indukcijom" putem vodikovih veza. Postignuti maksimalni enantiomerni višak (ee) iznosi ee(R) = 68%, ee(S) = 84% i ee(R) = 81% upotrebom monodentatnih A, B, odnosno bidentatnih C liganda. Pripravljeni su Pd(II) i Pt(II) kompleksi s A i B u svrhu ispitivanja interakcija među ligandima. Priređeni ligandi i njihovi metalni kompleksi okarakterizirani su različitim analitičkim metodama (1H, 13C, 31P NMR, COSY, NOESY, ESI-MS, MALDI-TOF HRMS, CD i difrakcija X-zraka na jediničnom kristalu), a stereokemija produkata reakcije hidrogeniranja objašnjena je stereokemijskom analizom i DFT izračunima.

Abstract (english)

Within this thesis, a total of 73 new ligands based on triphenylphosphine derivatives with aminoacids, short peptides and/or amines, were synthesized. The ligands were divided into three categories (A, B, and C) by the phosphine phenyl ring substitution and denticity. Their in situ prepared Rh(I) complexes were tested as catalysts in the enantioselective hydrogenation of model substrates, methyl-2-acetamidoprop-2-enoate (S1) and methyl-(Z)-2-acetamido-3-phenylprop-2-enoate (S2). Chiral information from distant amino acids is transmitted to the prochiral metal through "backdoor induction" via hydrogen bonding. The obtained maximal enantiomeric excess (ee) is ee(R) = 68 %, ee(S) = 84 % and ee(R) = 81 % using monodentate A, B, and bidentate C ligands, respectively. Pd(II) and Pt(II) complexes of A and B were synthesized as model compounds for examination of ligand interactions. The ligands and their metal complexes were characterized with different analytical methods (1H, 13C, 31P NMR, COSY, NOESY, ESI-MS, MALDI-TOF HRMS, CD, and single crystal X-ray diffraction). The stereochemistry of the hydrogenation products was explained using stereochemical analysis and DFT calculations.

• Keywords: posredna indukcija; enantioselektivna kataliza; vodikova veza; kiralnost; amino kiseline; rodij; trifenilfosfin
• Keywords (english): backdoor induction; enantioselective catalysis; hydrogen bond; chirality; aminoacids; rhodium; triphenylphosphine
• Language: croatian
• URN:NBN: urn:nbn:hr:217:372173
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 125 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-02-14 16:51:03