TY - JOUR AU - Császár, Zsófia AU - Pőrgye, Zsanett E. AU - Farsang, Evelin AU - Kovács, Margit AU - Bényei, Attila Csaba AU - Bakos, József AU - Farkas, Gergely TI - Ruthenium complexes of new chiral phosphine‐amine‐ether ligands (Ru‐PNO) for asymmetric hydrogenation – the role of backbone chirality in pincer ligand design JF - APPLIED ORGANOMETALLIC CHEMISTRY J2 - APPL ORGANOMET CHEM PY - 2024 SN - 0268-2605 DO - 10.1002/aoc.7379 UR - https://m2.mtmt.hu/api/publication/34555466 ID - 34555466 AB - New chiral phosphine‐amine‐ether (PNO) ligands of the general formula Ph 2 PCH(R 1 )(CH 2 ) n CH(R 1 )N(R 2 )CH(R 3 )CH 2 OMe, where R 1 , R 2 , and R 3 = H or Me, n = 0 or 1, and their ruthenium complexes of the type [RuCl 2 (PPh 3 )(PNO)] have been synthesized. The coordination compounds were characterized by 1D and 2D NMR spectroscopy, modeled by DFT calculations, and in one case analyzed by X‐ray crystallography. The combined spectroscopic and theoretical investigations revealed that the relative configuration of the stereogenic elements in the P–N and N–O backbone represents a crucial factor in determining the conformation of the pincer‐type chelates and may also affect the configuration of the coordinated stereogenic nitrogen in the NH subunit, an essential element of stereochemical communication in outer sphere bifunctional catalysis. The new complexes were applied in the asymmetric hydrogenation of fused ring bicyclic ketones (i.e., 1‐tetralone and 4‐chromanone derivatives), a challenging substrate class, where enantioselectivities up to 97% could be obtained. Based on the spectroscopic and theoretical studies and catalytic experiments, structural features affecting the stereochemistry of the coordination could be identified and a qualitative enantioinduction model has been proposed. LA - English DB - MTMT ER - TY - JOUR AU - Farkas, Gergely AU - Császár, Zsófia AU - Farsang, Evelin AU - Bényei, Attila Csaba AU - Bakos, József TI - Application of alkane-diyl based chiral phosphine-aminophosphine (P-NP) and thioether-aminophosphine (S-NP) ligands in Rh-catalyzed asymmetric hydrogenation JF - JOURNAL OF ORGANOMETALLIC CHEMISTRY J2 - J ORGANOMET CHEM VL - 994 PY - 2023 SN - 0022-328X DO - 10.1016/j.jorganchem.2023.122723 UR - https://m2.mtmt.hu/api/publication/33785458 ID - 33785458 LA - English DB - MTMT ER - TY - JOUR AU - Császár, Zsófia AU - Kovács, Regina AU - Fonyó, Máté AU - Simon, József AU - Bényei, Attila Csaba AU - Lendvay, György AU - Bakos, József AU - Farkas, Gergely TI - Testing the role of the backbone length using bidentate and tridentate ligands in manganese-catalyzed asymmetric hydrogenation JF - MOLECULAR CATALYSIS J2 - MOL CATAL VL - 529 PY - 2022 PG - 10 SN - 2468-8231 DO - 10.1016/j.mcat.2022.112531 UR - https://m2.mtmt.hu/api/publication/33059894 ID - 33059894 AB - Manganese complexes modified by simple alkane-diyl based P,N (Ph2PCH(CH3)(CH2)mCH(CH3)NHC2H5; m = 0, 1) and potentially tridentate P,N,N (Ph2PCH(CH3)(CH2)(m)CH(CH3)NH(CH2)(n)N(CH3)(2); m = 0, 1; n = 2, 3) type ligands have been synthesized and tested in the asymmetric hydrogenation of ketones. The combined coordination and catalytic studies led to the conclusion that the N-N tether length of the P,N,N type compounds plays a crucial role in determining the chemoselectivity, while the length of the P-N skeleton has been shown to affect the catalytic activity. Mn-catalysts containing P,N,N ligands with the proper tether lengths (m = 0, n = 1) provided high enantioselectivities (up to 95% ee) and activities in the asymmetric hydrogenation of acetophe-none derivatives. The influence of substitution of the acetophenone substrate and the reaction conditions is demonstrated. Based on quantum chemistry calculations, a qualitative model explaining the origin of enantio-selectivity is proposed. LA - English DB - MTMT ER - TY - JOUR AU - Császár, Zsófia AU - Guóth, Mária AU - Farsang, Evelin AU - Bényei, Attila Csaba AU - Bakos, József AU - Farkas, Gergely TI - Hydrogen bond-directed coordination of phosphine-amino-alcohol (P,N,OH) ligands: stereochemical considerations and catalytic studies JF - INORGANICA CHIMICA ACTA J2 - INORG CHIM ACTA VL - 543 PY - 2022 PG - 8 SN - 0020-1693 DO - 10.1016/j.ica.2022.121153 UR - https://m2.mtmt.hu/api/publication/33054254 ID - 33054254 AB - Novel phosphine-aminoalcohol type chiral ligands of the chemical formula Ph2PCH(CH3)CH2CH(CH3)NHCH(R)CH2OH (1a: (R,R)-(S), R = CH3, 1b: (S,S)-(S), R = CH3, 1c: (S,S), R = H) have been synthesized in two simple steps using cyclic sulfates. The coordination behavior of 1a-c having stereochemically labile nitrogen donor to square planar Pd(II) center was investigated by X-ray crystallography, 1D and 2D NMR methods and by DFT calculations. In the solid state of complex [Pd(1a)Cl2] an intramolecular hydrogen bond could be observed between the OH-moiety and one of the Cl co-ligands, while intermolecular hydrogen bonds were detected in the case of [Pd(1b)Cl2] between the same functionalities. In the dichloromethane solution of the complexes the hydrogen bond was identified as a crucial factor in determining ring conformation and nitrogen configuration. Ligand 1a coordinated stereoselectively to the metal in [Pd(1a)Cl2] leading to a complex having a single conformationally rigid six-membered chelate and a configurationally fixed N-donor. In contrast, coordination of ligands 1b-c resulted in the formation of a mixture of isomers with different chelate conformation and nitrogen configuration. The ligands were utilized in Pd-catalyzed asymmetric allylic alkylation where high enantioselectivities (ees up to 96 %) and activities could be obtained. LA - English DB - MTMT ER - TY - JOUR AU - Császár, Zsófia AU - Major, Máté Miklós AU - Bakos, József AU - Farkas, Gergely TI - Variációk négy donoratomra (P, N, S, O): a ligandum szerkezetének finomhangolása nagy hatékonyságú katalizátorok előállítására JF - MAGYAR KÉMIAI FOLYÓIRAT - KÉMIAI KÖZLEMÉNYEK (1997-) J2 - MAGY KÉM FOLY KÉM KÖZL VL - 127 PY - 2021 IS - 3-4 SP - 137 EP - 143 PG - 7 SN - 1418-9933 DO - 10.24100/MKF.2021.03-4.137 UR - https://m2.mtmt.hu/api/publication/32568616 ID - 32568616 N1 - "A kutatást az NKFIH K115539 és K128074 azonosító számú projektek támogatták." LA - Hungarian DB - MTMT ER - TY - JOUR AU - Major, Máté Miklós AU - Guoth, Maria AU - Balogh, Szabolcs AU - Simon, József AU - Bényei, Attila Csaba AU - Bakos, József AU - Farkas, Gergely TI - Novel Pd(PN,S)-complexes: Highly active catalysts designed for asymmetric allylic etherification JF - MOLECULAR CATALYSIS J2 - MOL CATAL VL - 512 PY - 2021 PG - 9 SN - 2468-8231 DO - 10.1016/j.mcat.2021.111763 UR - https://m2.mtmt.hu/api/publication/32235303 ID - 32235303 N1 - Funding Agency and Grant Number: National Excellence Program of the Ministry of Human Capacities [uNKP-18-3]; [NKFIH K128074] Funding text: We thank Mr Bela Edes for skillful assistance in analytical mea-surements and synthetic experiments. The scientific program was sup-ported by the project NKFIH K128074. The research was also supported by the uNKP-18-3 National Excellence Program of the Ministry of Human Capacities. AB - Six novel thioether-aminophosphine type ligands with a general formula (Ar1)2PN(R1)CHR2(CH2)nCH(R3)SAr2 has been synthesized. The modular structure of the ligands and the new methodologies developed for their preparation enabled the systematic variation of their bridge length (n = 0 or 1), the substitution pattern of the backbone (R2, R3 = H or Me) as well as the P-, N- and S-substituents (Ar1 = Ph or 3,5-Me2C6H3, R1 = Et or iPr and Ar2 = Ph, 4-MeC6H4, or 4-MeOC6H4, respectively). The ligands proved to be effective in Pd-catalyzed asymmetric allylic etherification reactions providing the products in high yields (up to 95%) and with good enantioselectivities (up to 86%) using unprecedentedly low (0.2 mol%) loadings of the chiral Pd-catalyst. Based on these findings, a new scalable protocol has been developed for the preparation of chiral allylic ethers. Furthermore, the Pd(II) coordination chemistry of the ligands was thoroughly investigated by 1D and 2D NMR methods as well as by X-ray crystallography with special attention to the conformation of the chelate ring and the stereoselectivity of the sulfur coordination. Based on these studies, the main factors determining activity and selectivity of the catalytic system have been identified. LA - English DB - MTMT ER - TY - CHAP AU - Farkas, Gergely AU - Madarász, József AU - Bakos, József ED - Phansavath, Phannarath ED - Ratovelomanana-Vidal, Virginie TI - Asymmetric Hydrogenation in Continuous-Flow Conditions T2 - Asymmetric Hydrogenation and Transfer Hydrogenation PB - Wiley-VCH Verlag SN - 9783527822294 PY - 2021 SP - 307 EP - 337 PG - 31 DO - 10.1002/9783527822294.ch10 UR - https://m2.mtmt.hu/api/publication/31995534 ID - 31995534 LA - English DB - MTMT ER - TY - JOUR AU - Major, Máté Miklós AU - Balogh, Szabolcs AU - Simon, József AU - Bakos, József AU - Farkas, Gergely TI - New chiral thioether-phosphite ligands and their rhodium-coordination chemistry: steric and electronic properties, dynamic processes and application in catalysis JF - JOURNAL OF COORDINATION CHEMISTRY J2 - J COORD CHEM VL - 74 PY - 2021 IS - 8 SP - 1311 EP - 1322 PG - 12 SN - 0095-8972 DO - 10.1080/00958972.2021.1892086 UR - https://m2.mtmt.hu/api/publication/31995530 ID - 31995530 N1 - Department of Organic Chemistry, University of Pannonia, Veszprém, Hungary NMR Laboratory, University of Pannonia, Veszprém, Hungary Department of Analytical Chemistry, University of Pannonia, Veszprém, Hungary Export Date: 18 November 2022 CODEN: JCCMB Correspondence Address: Bakos, J.; Department of Organic Chemistry, H-8200 Veszprém, Hungary Correspondence Address: Farkas, G.; Department of Organic Chemistry, H-8200 Veszprém, Hungary LA - English DB - MTMT ER - TY - CHAP AU - Major, Máté Miklós AU - Guóth, Mária AU - Balogh, Szabolcs AU - Bényei, Attila AU - Bakos, József AU - Farkas, Gergely ED - Egedy, Attila ED - Bárkányi, Ágnes TI - Királis kéntartalmú katalizátorok fejlesztése T2 - Pannon Egyetem, Mérnöki Kari Tudományos Konferencia 2020. szeptember 16. PB - Pannon Egyetem CY - Veszprém SN - 9789633961537 PY - 2020 SP - 27 UR - https://m2.mtmt.hu/api/publication/33813221 ID - 33813221 AB - Napjainkban nagy kihívást jelent a környezetkímélő vegyipari megoldások fejlesztése és ipari folyamtokba való integrálása. Egyes reakciók energiaigénye (hő és nyomás), valamint a keletkező melléktermék mennyisége is csökkenthető átmenetifém-komplexek alkalmazásával, így eleget tesznek a zöld kémia alapelveinek. Ipari folyamatokban biológiailag aktív vegyületek előállítására elterjedten alkalmaznak királis átmenetifém-komplexeket. E módszer előnye, hogy a sztereoszelektív reakció során a királis információ átadása rendkívül kis mennyiségű optikailag aktív katalizátor és nagy mennyiségű akirális vagy racém szubsztrátum között megy végbe. Munkám során tioéter-amin és tioéter-aminofoszfin ((S,N) és (S,PN)) ligandumokat tartalmazó Pd-katalizátorok fejlesztését tűztem ki célul. A katalizátortervezés folyamán vizsgáltam a ligandumok sztérikus és elektronikus tulajdonságainak hatását, valamint sikerült elvégeznem egyes komplexek konformáció-analízisét és megfigyelnem dinamikus tulajdonságait is. A ligandumokból „in situ” képzett Pd-katalizátorokat aszimmetrikus C-C kapcsolási reakcióban teszteltem. Megállapítottam, hogy a legígéretesebb Pd(S,N)-komplexek zöld oldószerben (propilén-karbonát) is alkalmazhatók, valamint felhasználásukkal a szakirodalomban is kiemelkedő 93%-os enantioszelektivitást sikerült elérnem. A tioéter-amin ligandumok módosításával tioéter-aminofoszfin ligandumokat sikerült előállítanom. Utóbbi vegyületek palládiummal alkotott komplexei a Pd(S,N) típusú katalizátoroknál aktívabbak, ezen kívül alkalmasak sztereoszelektív C-C, C-N és C-O kapcsolási reakciók kivitelezésére is. Utóbbi reakciót részletesen vizsgálatam, és összefüggést állapítottam meg a komplexek szerkezete, a nukleofil ágens (alkohol) és az oldószer minősége, valamint a reakció aktivitása és szelektivitása között. A Pd(S,PN)-komplexek kiváló aktivitását jelzi, hogy a vizsgált reakció mindössze 0,2 mol% katalizátor jelenlétében szobahőmérsékleten, 24 órán belül jó enantioszelektivitással lejátszódik, mely a tématerületen kiemelkedő eredménynek számít. LA - Hungarian DB - MTMT ER - TY - JOUR AU - Császár, Zsófia AU - Szabo, Eszter Z. AU - Bényei, Attila Csaba AU - Bakos, József AU - Farkas, Gergely TI - Chelate ring size effects of Ir(P,N,N) complexes: Chemoselectivity switch in the asymmetric hydrogenation of alpha,beta-unsaturated ketones JF - CATALYSIS COMMUNICATIONS J2 - CATAL COMMUN VL - 146 PY - 2020 PG - 5 SN - 1566-7367 DO - 10.1016/j.catcom.2020.106128 UR - https://m2.mtmt.hu/api/publication/31625235 ID - 31625235 N1 - Funding Agency and Grant Number: EU - European Regional Development FundEuropean Union (EU) [GINOP-2.3.2-15-2016-00008, GINOP-2.3.3-15-2016-00004]; [NKFIH K128074] Funding text: We thank Mr. Bela Edes for skillful assistance in analytical measurements and synthetic experiments. The research was supported by the project NKFIH K128074. The research was also supported by the EU and co-financed by the European Regional Development Fund under the projects GINOP-2.3.2-15-2016-00008 and GINOP-2.3.3-15-2016-00004. Department of Organic Chemistry, University of Pannonia, Egyetem u. 10, Veszprém, H-8200, Hungary Department of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, Debrecen, H-4032, Hungary Export Date: 6 February 2021 CODEN: CCAOA Correspondence Address: Farkas, G.; Department of Organic Chemistry, Egyetem u. 10, Hungary; email: gerifarkas@almos.uni-pannon.hu Funding details: European Commission, EC Funding details: European Regional Development Fund, FEDER, GINOP-2.3.2-15-2016-00008, GINOP-2.3.3-15-2016-00004 Funding text 1: We thank Mr. Béla Édes for skillful assistance in analytical measurements and synthetic experiments. The research was supported by the project NKFIH K128074 . The research was also supported by the EU and co-financed by the European Regional Development Fund under the projects GINOP-2.3.2-15-2016-00008 and GINOP-2.3.3-15-2016-00004 . AB - A novel, highly modular approach has been developed for the synthesis of new chiral P,N,N ligands with the general formula Ph2P(CH3)CH(CH2)mCH(CH3)NHCH2CH2(CH2)nN(CH3)(2) and Ph2P(CH3)CHCH2CH(CH3)NHCH2(CH2)(n)-2-Py (m, n = 0, 1). The systematic variation of their P-N and N-N backbone led to the conclusion that the activity, chemoand enantioselectivity in the hydrogenation of alpha,beta-unsaturated ketones are highly dependent on the combination of the two bridge lengths. It has been found that a minor change in the ligand's structure, i. e. varying the value of m from 1 to 0, can switch the chemoselectivity of the reaction, from 80% C=O to 97% C=C selectivity. LA - English DB - MTMT ER -