3187-83-5Relevant articles and documents
Stereoselective protonation of 2-methyl-1-tetralone lithium enolate catalyzed by salan-type diamines
?owicki, Daniel,Watral, Justyna,Jelecki, Maciej,Bohusz, Wiktor,Kwit, Marcin
, (2021/04/02)
Asymmetric protonation of ketone enolates is a convenient alternative to asymmetric alkylation of enolates that allows to convert racemic ketones into their optically active form. Here, we have reported an efficient enantioselective protonation of 2-methyl-1-tetralone lithium enolate catalyzed by salan-type diamines. A broad series of salan-type catalysts were synthesized, including several previously unknown, and subsequently tested in the title reaction. For the first time, a chiral amine used as organocatalyst has shown better results than as stoichiometric protonating agent. Application of only 10 mol% of salan allows to obtain the title ketone with high yield and enantiomeric excess up to 75%. The DFT calculations of the structure of the catalyst and its complex with lithium enolate were conducted, which makes it possible to propose a likely reaction mechanism.
Polymerization of Ethylene in the Presence of Titanium(IV), Zirconium(IV), and Vanadium(V) Coordination Compounds with Salen Ligands
Bulychev, B. M.,Gagieva, S. Ch.,Lyadov, A. S.,Takazova, R. U.,Tuskaev, V. A.
, p. 291 - 297 (2020/05/25)
Abstract: Coordination compounds of titanium(IV), zirconium(IV), and vanadium(V) with chiral salen ligands have been obtained and characterized, and their catalytic activity in the polymerization reaction of ethylene has been studied. It has been shown that in the presence of polymethylaluminoxane as a cocatalyst, the activity of the titanium-containing catalyst system reaches 944 kgPE mol(Ti)?1 h?1 and leads to the preparation of ultrahigh-molecular-weight polyethylene.
Stabilized Ru[(H2O)6]3+ in Confined Spaces (MOFs and Zeolites) Catalyzes the Imination of Primary Alcohols under Atmospheric Conditions with Wide Scope
Mon, Marta,Adam, Rosa,Ferrando-Soria, Jesús,Corma, Avelino,Armentano, Donatella,Pardo, Emilio,Leyva-Pérez, Antonio
, p. 10401 - 10406 (2018/10/24)
Imines are ubiquitous intermediates in organic synthesis, and the metal-mediated imination of alcohols is one of the most direct and simple methods for their synthesis. However, reported protocols lack compatibility with many other functional groups since basic supports/media, pure oxygen atmospheres, and/or released hydrogen gas are required during reaction. Here we show that, in contrast to previous metal-catalyzed methods, hexa-aqueous Ru(III) catalyzes the imination of primary alcohols with very wide functional group tolerance, at slightly acid pH and under low oxygen atmospheres. The inorganic metal complex can be supported and stabilized, integrally, within either faujasite-type zeolites (Y and X) or a metal organic framework (MOF), to give a reusable heterogeneous catalyst which provides an industrially viable process well below the flammability limit of alcohols and amines.