36741-70-5Relevant academic research and scientific papers
Chromium-Catalyzed Linear-Selective Alkylation of Aldehydes with Alkenes
Hirao, Yuki,Kanai, Motomu,Katayama, Yuri,Mitsunuma, Harunobu
supporting information, (2020/11/18)
We developed a chromium-catalyzed, photochemical, and linear-selective alkylation of aldehydes with alkylzirconium species generated in situ from a wide range of alkenes and Schwartz's reagent. Photochemical homolysis of the C-Zr bond afforded alkyl radicals, which were then trapped by a chromium complex catalyst to generate the alkylchromium(III) species for polar addition to aldehydes. The reaction proceeded with high functional group tolerance at ambient temperature under visible-light irradiation.
Nozaki-Hiyama-Kishi reactions catalytic in chromium
Fürstner, Alois,Shi, Nongyuan
, p. 12349 - 12357 (2007/10/03)
A procedure is described which allows for the first time to perform chromium-catalyzed additions of organic halides to aldehydes ("Nozaki-Hiyama-Kishi reactions"). The reactions are mediated by trimethylchlorosilane, and the active Cr2+ species is constantly recycled by means of nontoxic, commercial manganese powder as the stoichiometric reductant. This method nicely applies to different substituted aryl, heteroaryl, alkynyl, alkenyl, and allyl halides as well as to alkenyl inflates as the starting materials and rivals its stoichiometric precedent in terms of efficiency, practicability, and chemo- and diastereoselectivity. Specifically, it has been demonstrated that the addition of crotyl bromide to various aldehydes is highly stereoconvergent, i.e. the respective anti-configurated homoallyl alcohols are obtained with excellent diastereomeric excess independent of whether the starting halide is (E)- or (Z)-configurated. In accordance with the likely catalytic cycle, both CrCl2(cat.) or CrCl3(cat) turned out to efficiently mediate reactions of this type, with the latter being preferred for practical reasons. Finally, attempts were made to optimize the number of turnovers in chromium. In this context the use of either chromocene (Cp2Cr) or CpCrCl2·THF as "pre-catalysts" were found to significantly upgrade the efficiency of such C-C bond formations, with ≤ 1 mol % of chromium being required in these cases for quantitative conversions.
New Route to N-(Dialkylaminoalkyl)benzamides
Sitsun', Van,Borisova, E. Ya.,Golovkov, P. V.,Burdelev, O. T.,Guzeneva, N. A.,et al.
, p. 1063 - 1065 (2007/10/03)
A new method is developed for preparing N-(dialkylaminoalkyl)benzamides with a secondary or tertiary carbon atom at the amide nitrogen atom by condensation of chloro alcohols with nitriles in strongly acidic media, followed by amination of the resulting c
