Abstract: Two bioinspired hydroxo‐bridged diferric complexes 6 and 7 with N4‐donor ligands of the PDP type (PDP=N,N′‐bis(pyridin‐2‐ylmethyl)‐2,2′‐bipyrrolidine), differing by substituents at the pyridine rings (4‐NMe2 in 7 vs. 3,5‐Me2‐4‐OMe in 6), efficiently catalyze the enantioselective alkene epoxidation with H2O2 and peracetic acid in the presence of a carboxylic acid additive (up to 99 catalyst turnover numbers, TON, toward epoxide, up to 94 % ee). Catalyst systems based on complex 7 display the high‐spin perferryl intermediate 7 aAA (S=3/2, g1, g2=3.69, g3=1.96), whereas catalyst systems based on complex 6 exhibit the low‐spin perferryl intermediate 6 aAA (S=1/2, g1=2.07, g2=2.01, g3=1.96). The S=3/2 and the S=1/2 intermediates directly react with cyclohexene and cyclohexane at low temperatures (−40 °C and −85 °C, respectively). The catalyst systems, exhibiting less reactive intermediate 7 aAA, demonstrate higher enantioselectivity (% ee) in the epoxidation of chalcone. The origin of the unprecedented high‐spin state of the perferryl intermediate is discussed.

Cite: Zima A.M. , Lyakin O.Y. , Bryliakov K.P. , Talsi E.P.
High‐Spin and Low‐Spin Perferryl Intermediates in Fe(PDP)‐Catalyzed Epoxidations
ChemCatChem. 2019. V.11. N21. P.5345-5352. DOI: 10.1002/cctc.201900842 WOS Scopus РИНЦ ANCAN OpenAlex

Dates:

Submitted:	May 8, 2019
Accepted:	Jun 24, 2019
Published online:	Jul 2, 2019
Published print:	Nov 7, 2019

Identifiers:

Web of science:	WOS:000479743500001
Scopus:	2-s2.0-85070323488
Elibrary:	41640040
Chemical Abstracts:	2019:1459436
Chemical Abstracts (print):	171:505623
OpenAlex:	W2955941875

Citing:

DB	Citing
Scopus	18
Web of science	16
Elibrary	20
OpenAlex	21

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