18510-49-1Relevant academic research and scientific papers
Sterically crowded aryloxide compounds of silicon
Healy, Matthew D.,Barron, Andrew R.
, p. 165 - 172 (1990)
The interaction of one equivalent of NaBHT (BHT-H = butylated hydroxytoluene) with Me3SiCl, Me2SiCl2 and SiCl4 gives Me3Si(BHT) (1), Me2SiCl(BHT) (2) and Cl3Si(BHT) (3), respectively, which have been characterized by 1H NMR, IR spectroscopy and elemental
Insertion of CO2 and COS into Bi-C bonds: Reactivity of a bismuth NCN pincer complex of an oxyaryl dianionic ligand, [2,6-(Me 2NCH2)2C6H3]Bi(C 6H2tBu2O)
Kindra, Douglas R.,Casely, Ian J.,Fieser, Megan E.,Ziller, Joseph W.,Furche, Filipp,Evans, William J.
, p. 7777 - 7787 (2013/07/19)
The reactivity of the unusual oxyaryl dianionic ligand, (C 6H2tBu2-3,5-O-4)2-, in the Bi3+ NCN pincer complex Ar′Bi(C6H 2tBu2-3,5-O-4), 1, [Ar′ = 2,6-(Me 2NCH2)2C6H3] has been explored with small molecule substrates and electrophiles. The first insertion reactions of CO2 and COS into Bi-C bonds are observed with this oxyaryl dianionic ligand complex. These reactions generate new dianions that have quinoidal character similar to the oxyaryl dianionic ligand in 1. The oxyarylcarboxy and oxyarylthiocarboxy dianionic ligands were identified by X-ray crystallography in Ar′Bi[O2C(C6H2 tBu2-3-5-O-4)-κ2O,O′], 2, and Ar′Bi[OSC(C6H2tBu2-3-5-O-4)- κ2O,S], 3, respectively. Silyl halides and pseudohalides, R3SiX (X = Cl, CN, N3; R = Me, Ph), react with 1 by attaching X to bismuth and R3Si to the oxyaryl oxygen to form Ar′Bi(X)(C6H2tBu2-3,5- OSiR3-4) complexes, a formal addition across five bonds. These react with additional R3SiX to generate Ar′BiX2 complexes and R3SiOC6H3tBu2-2,6. The reaction of 1 with I2 forms Ar′BiI2 and the coupled quinone, 3,3′,5,5′-tetra-tert-butyl-4,4′- diphenoquinone, by oxidative coupling.
A novel approach towards intermolecular stabilization of para-quinone methides. First complexation of the elusive, simplest quinone methide, 4-methylene-2,5-cyclohexadien-1-one
Rabin, Oded,Vigalok, Arkadi,Milstein, David
, p. 454 - 462 (2007/10/03)
A novel approach towards the intermolecular stabilization of "simple" (i.e. methylene-unsubstituted) p-quinone methides (QMs) by their coordination to a transition-metal center is described. 4-Bromomethyl phenols, protected by a silyl group, were employed as the QM precursors and cis-chelating diphosphine Pd0 complexes were chosen as the metal precursors, since they have strong back-bonding interactions with the electron-poor QM moiety. Removal of the silyl protecting-group from the corresponding [LPd(benzyl)Br] complex (L=bisphosphine) with fluoride results in the spontaneous rearrangement of the unobserved zwitterionic PdII complex into the QM-Pd0 complex. The feasibility of this approach was demonstrated in the synthesis of the structurally characterized Pd0 complex of BHT-QM (4), a biologically relevant metabolite of 2,6-di-tert-butyl-p-cresol, and the synthesis of the complex of 4-methylene-2,5-cyclohexadien-1-one (11), the simplest, and so far unobserved QM molecule. These complexes exhibit a remarkable thermal stability and do not react with alcohol or water. In both cases, the use of an appropriate incoming ligand allowed the release of the coordinated QM into the reaction media in which it was effectively trapped by added nucleophiles.
Structures of Three Lithium Ester Enolates by X-ray Diffraction: Derivation of Reaction Path for Cleavage into Ketene and Alcoholate
Seebach, Dieter,Amstutz, Rene,Laube, Thomas,Schweizer, W. Bernd,Dunitz, Jack D.
, p. 5403 - 5409 (2007/10/02)
Crystal structure analyses have been carried out for lithium enolates of the following three esters: tert-butyl propionate ((Z)-1), tert-butyl 2-methylpropionate (2), and methyl 3,3-dimethylbutanoate ((Z)-3).Enolates (Z)-1 and 2 are dimeric (with one TMED
