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001-es BibID:BIBFORM107565
035-os BibID:(Cikkazonosító)121153 (WoS)000849920300005 (Scopus)85136453241
Első szerző:Császár Zsófia (vegyész)
Cím:Hydrogen bond-directed coordination of phosphine-amino-alcohol (P,N,OH) ligands: Stereochemical considerations and catalytic studies / Zsófia Császár, Mária Guóth, Evelin Farsang, Attila C. Bényei, József Bakos, Gergely Farkas
Dátum:2022
ISSN:0020-1693 1873-3255
Megjegyzések: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)Cl-2] 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)Cl-2] 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)Cl-2] 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.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Inorganica Chimica Acta. - 543 (2022), p. 1-8. -
További szerzők:Guóth Mária Farsang Evelin Bényei Attila (1962-) (vegyész) Bakos József (vegyész) Farkas Gergely
Pályázati támogatás:K128074
Egyéb
TKP2021-NKTA-21
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Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM102830
035-os BibID:(WOS)000686886000002 (Scopus)85111256236 (cikkazonosító)111763
Első szerző:Major Máté
Cím:Novel Pd(PN,S)-complexes : highly active catalysts designed for asymmetric allylic etherification / Máté M. Major, Mária Guóth, Szabolcs Balogh, József Simon, Attila C. Bényei, József Bakos, Gergely Farkas
Dátum:2021
ISSN:2468-8231
Megjegyzések: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.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Thioether-aminophosphine Allylic etherification Stereoselective coordination Palladium catalysis
Megjelenés:Molecular Catalysis. - 512 (2021), p. 1-9. -
További szerzők:Guóth Mária Balogh Szabolcs Simon József Bényei Attila (1962-) (vegyész) Bakos József (gyógyszerész) Farkas Gergely
Pályázati támogatás:NKFIH K128074
Egyéb
Internet cím:Szerző által megadott URL
DOI
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