79014-35-0Relevant academic research and scientific papers
Alkyne hydroamination and trimerization with titanium bis(phenolate) pyridine complexes: Evidence for low-valent titanium intermediates and synthesis of an ethylene adduct of titanium(II)
Tonks, Ian A.,Meier, Josef C.,Bercaw, John E.
, p. 3451 - 3457 (2013/07/26)
A class of titanium precatalysts of the type (ONO)TiX2 (ONO = pyridine-2,6-bis(4,6-di-tert-butylphenolate); X = Bn, NMe2) has been synthesized and crystallographically characterized. The (ONO)TiX2 (X = Bn, NMe2, X2 = NPh) complexes are highly active precatalysts for the hydroamination of internal alkynes with primary arylamines and some alkylamines. A class of titanium imido/ligand adducts, (ONO)Ti(L)(NR) (L = HNMe2, py; R = Ph, tBu), have also been synthesized and characterized and provide structural analogues to intermediates on the purported catalytic cycle. Furthermore, these complexes exhibit unusual redox behavior. (ONO)TiBn2 (1) promotes the cyclotrimerization of electron-rich alkynes, likely via a catalytically active TiII species that is generated in situ from 1. Depending on reaction conditions, these TiII species are proposed to be generated through Ti benzylidene or imido intermediates. A formally TiII complex, (ONO)Ti II(η2-C2H4)(HNMe2) (7), has been prepared and structurally characterized.
An efficient, scaleable procedure for the conversion of esters to isoxazoles
Bunnelle,Singam,Narayanan,Bradshaw,Liou
, p. 439 - 442 (2007/10/03)
A concise, regiocontrolled route to isoxazoles, based on the condensation of an ester with a metallated imine, has been developed. The intermediate vinylogous amides react smoothly with hydroxylamine to provide, after dehydration, substituted isoxazoles. The method has been used for the multi-kilo scale preparation of ABT-418, a novel cholinergic channel activator.
Boron Compounds, L. - Diethyl(substituted-vinylamino)boranes from Triethylborane and N-Alkylketimines
Koester, Roland,Fenzl, Wolfgang,Levelt, Franciscus J.
, p. 734 - 747 (2007/10/02)
N-Alkylketimines 1 react with activated triethylborane above 70 deg C with liberation of 1 mol ethane to yield 81-97percent diethyl(substit.-vinylamino)boranes 2 1)-C(CH2R2)=CHR3>. (Z)-2b2 1 = CH(CH3)2, R2 = H, R3 = CH3> can be enriched to more than 80percent of 2b mixture by addition of 2b1 1 = CH(CH3)2, R2 = CH3, R3 = H> and (E)-2b2 to benzaldehyde.
