Insertion Chemistry of Yttrium Complex Cp*2Y(2-pyridyl) and Molecular Structure of an Unexpected CO Insertion Product (Cp*2Y)2(.mu.-.eta.2:.eta.2-OC(NC5H4)2)

Abstract

Insertion Chemistry of Cp*2Y(2-pyridyl) and Molecular Structure of the Unexpected CO Insertion Product (Cp*2Y)2(μ-η2 Deelman, Berth-Jan; Stevels, Willem M.; Teuben, Jan H.; Lakin, Miles T.; Spek, Anthony L. IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document VersionPublisher's PDF, also known as Version of record Publication date : 1994 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Deelman, B-J., Stevels, W. M., Teuben, J. H., Lakin, M. T., & Spek, A. L. (1994). Insertion Chemistry of Cp*2Y(2-pyridyl) and Molecular Structure of the Unexpected CO Insertion Product (Cp*2Y)2(μ-η2: η2-OC(NC5H4)2). Organometallics, 13(10). https://doi.org/10.1021/om00022a025 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Pyridine is metalated selectively at the 2-position by (Cp*zYH)z to yield Cp*zY(2-pyridyl) (1). Compound 1 reacts with HZ to give the hydride addition product Cp*zY(NC5Hs) (2). With THF and pyridine the adducts Cp*~Y(~,P-2-pyridyl)(THF) (3) and Cp*2Y(q1-2-pyridyl)-(py) (4) are formed. The pyridine complex 4 is not stable at higher temperatures, and after organic work up a stoichiometric amount of the C-C coupling product 2,2'-bipyridine is obtained. Ethylene and propylene react with 1 to give the monoinsertion products Cp*zYCHzCHz(2-NC5H4) (5) and C~* Z Y C H Z C H M~(~-N C~H~) (6). With alkynes HCCR, C-H activation to form the acetylides Cp*zY(CCR)(py) (7, R = H; 8, R = Me) is the dominant reaction. Also with 2-butyne C-H activation is observed yielding the propargylic metalation product Cp*zYCHzCCMe (9). 2-Pentyne gives a mixture of insertion products Cp*zY-(CEtCMe(2-NC5H4)) (10) and Cp*zY(CMeCEt(2-NCsH4)) (11). metathesis with pyridine to form 1 and 2-ethylpyridine. By using 1 as a catalyst, alkylation of pyridine to 2-ethylpyridine is possible. Also minor amounts of 2-n-butylpyridine, 2-nhexylpyridine, and polyethylene were formed in this catalytic process. Compound 5 is not thermally stable and decomposes to the isomers C~* Z Y (~-N C~H~(~-E~) ) (13) and Cp*zYCHMe-(2-NCsH4) (14) at 80 "C (60:40). Attempts to convert 5 to 1 and 2-ethylpyridine by hydrogenolysis of the Y-C bond also resulted in the formation of a mixture of 13 and 14 (5545). In this reaction the formation of a n intermediate hydride complex seems likely because (Cp*zYH>z and 2...

Insertion reactions of scandium pyridyl complexes supported by a ferrocene diamide ligand

“…The zirconocene pyridyl cationic complex reported by Jordan et al inserted 2-butyne to form a five-member azometallocycle (Scheme 1) [10]. The yttrocene pyridyl complex reported by Teuben et al showed different reactivity behavior: instead of an insertion reaction, a protonation reaction involving the methyl butyne protons took place (Scheme 2) [32]. The reaction between 2-py Ph and 2-butyne led to the isolation of an insertion product, 4-py Ph , analogous to the one obtained with the zirconocene complex (Eq.…”

“…Reaction of a yttrocene pyridyl complex with 2-butyne and 1,3-butadiene [32]. As part of our attempt to compare the reactivity of scandium pyridyl complexes with the reactivity of analogous yttrium and zirconium complexes, we also carried out the reaction with 1,3-butadiene (Eq.…”

“…(4)). Teuben reported that butadiene did not react with the yttrium complex Cp* 2 Y( 2 -N,C-pyridyl) [32]. No information related to a reaction of butadiene with the zirconium cationic pyridyl complexes could be found in the reports published by Jordan [10].…”

Half-Sandwich Rare-Earth-Catalyzed Olefin Polymerization, Carbometalation, and Hydroarylation

“…Neutral yttrium metallocene complexes could catalyze the ethylation of pyridine with ethylene at high pressure (40 bar) and high temperature (110°C) but showed no activity for higher olefins. 41 In contrast, the cationic half-sandwich rare-earth alkyl complexes served as excellent catalysts for the C−H alkylation of pyridines …”

C–C coupling reaction of pyridine derivatives at the dimethyl rare-earth metal cation [YMe2(THF)5]+: A DFT investigation

“…Early transition metal complexes often react with N-heterocycles to lead to ortho-metalated complexes [1e11]. Two examples for reductive coupling of pyridyl functions were reported in the literature: Teuben et al [2] have shown that thermolysis of Cp * 2 Y(h 2 -C,N-pyridyl) with excess pyridine led to the formation of 2,2 0 -bipyridine under H 2 elimination. Cummins et al [12] observed a CeC coupling between two pyridine ligands in the presence of H 2 in tantalum(V) chemistry, leading to a bipyridine complex.…”