ORCID Profile
0000-0002-0055-5335
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Publisher: Royal Society of Chemistry (RSC)
Date: 2008
DOI: 10.1039/B812147H
Abstract: Subjecting furan to sodium-mediated magnesiation via the new heteroleptic alkyl-amido reagent [(TMEDA).Na(CH(2)SiMe(3))(TMP)Mg(TMP)] produces the remarkable dodecasodium-hexamagnesium molecule [{(TMEDA)(3)Na(6)Mg(3)(CH(2)SiMe(3))(2,5-C(4)H(2)O)(3)(2-C(4)H(3)O)(5)}(2)], built upon a bridge network of 10 monodeprotonated and 6 twofold-deprotonated furan ligands.
Publisher: American Chemical Society (ACS)
Date: 04-03-2009
DOI: 10.1021/OM801135D
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CC10193E
Abstract: Treating fluorenone or 2-benzoylpyridine with the sodium zincate [(TMEDA)·Na(μ-(t)Bu)(μ-TMP)Zn((t)Bu)] in hexane solution, gives efficient (t)Bu addition across the respective organic substrate in a highly unusual 1,6-fashion, producing isolable organometallic intermediates which can be quenched and aerobically oxidised to give 3-tert-butyl-9H-fluoren-9-one and 2-benzoyl-5-tert-butylpyridine respectively.
Publisher: Wiley
Date: 05-01-2009
Abstract: With the aim of introducing the diisopropylamide [NiPr(2)](-) ligand to alkali-metal-mediated manganation (AMMMn) chemistry, the temperature-dependent reactions of a 1:1:3 mixture of butylsodium, bis(trimethylsilylmethyl)manganese(II), and diisopropylamine with ferrocene in hexane/toluene have been investigated. Performed at reflux temperature, the reaction affords the surprising, ferrocene-free, hydrido product [Na(2)Mn(2) (mu-H)(2){N(iPr)(2)}(4)]2 toluene (1), the first Mn hydrido inverse crown complex. Repeating the reaction rationally, excluding ferrocene, produces 1 in an isolated crystalline yield of 62 %. At lower temperatures, the same bimetallic amide mixture leads to the manganation of ferrocene to generate the first trimanganese, trinuclear ferrocenophane, [{Fe(C(5)H(4))(2)}(3){Mn(3)Na(2)(NiPr(2))(2) (HNiPr(2))(2)}] (2) in an isolated crystalline yield of 81 %. Both 1 and 2 have been characterised by X-ray crystallographic studies. The magnetic properties of paramagnetic 1 and 2 have also been examined by variable-temperature magnetisation measurements on powdered s les. For 1, the room-temperature value for chiT is 3.45 cm(3) K mol(-1), and on lowering the temperature a strong antiferromagnetic coupling between the two Mn ions is observed. For 2, the room-temperature value for chiT is 4.06 cm(3) K mol(-1), which is significantly lower than the expected value for three isolated paramagnetic Mn(II) ions.
Publisher: Wiley
Date: 17-12-2007
Publisher: Springer Science and Business Media LLC
Date: 23-05-2010
DOI: 10.1038/NCHEM.667
Abstract: The cleavage of ethers is commonly encountered in organometallic chemistry, although rarely studied in the context of new, emerging bimetallic reagents. Recently, it was reported that a bimetallic sodium-zinc base can deprotonate cyclic tetrahydrofuran under mild conditions without opening its heterocyclic (OC(4)) ring. In marked contrast to this synergic sedation, herein we show that switching to the more reactive sodium-magnesium or sodium-manganese bases promotes cleavage of at least six bonds in tetrahydrofuran, but uniquely the ring fragments are captured in separate crystalline complexes. Oxide fragments occupy guest positions in bimetallic, inverse crown ethers and C(4) fragments ultimately appear in bimetallated butadiene molecules. These results demonstrate the special synergic reactivity that can be executed by bimetallic reagents, which include the ability to capture and control, and thereby study, reactive fragments from sensitive substrates.
Publisher: Wiley
Date: 29-07-2008
No related grants have been discovered for Jan Klett.