5911-04-6Relevant articles and documents
The tantalum-catalyzed carbozincation of 1-alkenes with zinc dialkyls
Sultanov, Rifkat M.,Samoilova, Elena V.,Popod'Ko, Natal'Ya R.,Sabirov, Denis Sh.,Dzhemilev, Usein M.
, p. 23 - 29 (2015/02/19)
The TaCl5-mediated reaction between monosubstituted alkenes and Et2Zn affords 3-(R-substituted)-n-butylzincs in high yield (up to 92%) and regioselectivity. Organozinc reagents bearing a longer alkyl chain (R = Prn, Bun, Amn, Hexn) react with 1-alkenes in the presence of TaCl5 as the catalyst to give two types of organozinc compound having iso-alkyl structure. The probable mechanism of the carbozincation reaction implies the formation of β-substituted and β,β'-disubstituted tantalacyclopentanes as the key intermediates. The thermodynamic probability of the mechanistic elementary stages for the ethylzincation of terminal alkenes has been estimated using DFT PBE/SBK method.
Unusual pathway of the tantalum-catalyzed carboalumination reaction of alkenes with triethylaluminum
Sultanov, Rifkat M.,Samoilova, Elena V.,Popod'Ko, Natal'Ya R.,Tulyabaev, Artur R.,Sabirov, Denis Sh.,Dzhemilev, Usein M.
supporting information, p. 6619 - 6623 (2013/11/19)
Carboalumination of 1-alkenes (1-hexene, 1-octene, 1-decene) with Et 3Al in the presence of catalytic amounts of TaCl5 results in a mixture of 2-(R-substituted)- and 3-(R-substituted)-n-butylaluminums (1:1 ratio) in total yields of 75-85%. The TaCl5-catalyzed reaction of bicyclo[2.2.1]hept-2-ene, endo-tricyclo[5.2.1.02,6]deca-3,8-diene, and (exo/endo)-5-methylbicyclo[2.1.1]hept-2-ene with Et3Al leads to the formation of diethyl[2-exo-(2′-norbornylethyl)]aluminums in high yields. DFT calculations confirm the thermodynamic preference of the final exo product. The multistep reaction mechanisms for the formation of the resultant organoaluminums through tantalacyclopentanes as key intermediates are also discussed.
New zeolite Al-COE-4: Reaching highly shape-selective catalytic performance through interlayer expansion
Yilmaz, Bilge,Müller, Ulrich,Feyen, Mathias,Zhang, Haiyan,Xiao, Feng-Shou,De Baerdemaeker, Trees,Tijsebaert, Bart,Jacobs, Pierre,De Vos, Dirk,Zhang, Weiping,Bao, Xinhe,Imai, Hiroyuki,Tatsumi, Takashi,Gies, Hermann
, p. 11549 - 11551 (2013/01/15)
A ferrierite-type layered aluminosilicate, Al-RUB-36, was prepared for the first time and its interlayer expansion resulted in new zeolite catalysts denoted Al-COE-3 and Al-COE-4. Decane hydroconversion tests demonstrated the highly active and shape-selective nature of the new Al-COE-4 catalyst with an unprecedented isomerization yield, highlighting the potential of this material as a hydroisomerization catalyst. This is the first report on achieving shape-selectivity via interlayer expansion. The Royal Society of Chemistry 2012.