615581-44-7Relevant academic research and scientific papers
A General Regioselective Synthesis of Alcohols by Cobalt-Catalyzed Hydrogenation of Epoxides
Beller, Matthias,Junge, Kathrin,Leischner, Thomas,Li, Wu,Liu, Weiping
, p. 11321 - 11324 (2020/05/16)
A straightforward methodology for the synthesis of anti-Markovnikov-type alcohols is presented. By using a specific cobalt triphos complex in the presence of Zn(OTf)2 as an additive, the hydrogenation of epoxides proceeds with high yields and selectivities. The described protocol shows a broad substrate scope, including multi-substituted internal and terminal epoxides, as well as a good functional-group tolerance. Various natural-product derivatives, including steroids, terpenoids, and sesquiterpenoids, gave access to the corresponding alcohols in moderate-to-excellent yields.
Visible-Light-Mediated Anti-Markovnikov Hydration of Olefins
Hu, Xia,Zhang, Guoting,Bu, Faxiang,Lei, Aiwen
, p. 1432 - 1437 (2017/08/09)
Considering that stoichiometric borane and oxidant are required in the classical alkene anti-Markovnikov hydration process, it remains appealing to achieve the transformation in a catalytic protocol. Herein, a visible-light-mediated anti-Markovnikov addition of water to alkenes by using an organic photoredox catalyst in conjunction with a redox-active hydrogen atom donor was developed, which avoided the need for a transition-metal catalyst, stoichiometric borane, as well as oxidant. Both terminal and internal olefins are readily accommodated in this transformation to obtain corresponding primary and secondary alcohols in good yields with single regioselectivity. This procedure can be scaled up to gram scale with a 230 turnover number based on photocatalyst.
Nickel-catalyzed regiodivergent opening of epoxides with aryl halides: Co-catalysis controls regioselectivity
Zhao, Yang,Weix, Daniel J.
supporting information, p. 48 - 51 (2014/01/23)
Epoxides are versatile intermediates in organic synthesis, but have rarely been employed in cross-coupling reactions. We report that bipyridine-ligated nickel can mediate the addition of functionalized aryl halides, a vinyl halide, and a vinyl triflate to epoxides under reducing conditions. For terminal epoxides, the regioselectivity of the reaction depends upon the cocatalyst employed. Iodide cocatalysis results in opening at the less hindered position via an iodohydrin intermediate. Titanocene cocatalysis results in opening at the more hindered position, presumably via TiIII-mediated radical generation. 1,2-Disubstituted epoxides are opened under both conditions to form predominantly the trans product.
Samarium(II)-promoted radical spirocyclization onto an aromatic ring
Ohno, Hiroaki,Okumura, Mitsuaki,Maeda, Shin-Ichiro,Iwasaki, Hiroki,Wakayama, Ryutaro,Tanaka, Tetsuaki
, p. 7722 - 7732 (2007/10/03)
Samarium(II)-mediated spirocyclization onto an aromatic ring was achieved by the reaction of methyl 4-(4-oxoalkyl)benzoates with SmI2 in the presence of i-PrOH and HMPA, yielding methyl 1-alkyl-1-hydroxyspiro[4.5]dec-6-ene-8-carboxylates in moderate to high yields. Utilizing this chemistry, spiro[3.5] and -[5.5] systems, and sterically congested spiro[4.5] systems, were easily synthesized. For the successful conversion, appropriate activation of the aromatic ring has proven to be extremely important: while an ester or amide functionality on the aromatic ring can promote the spirocyclization, a sulfonamide substituent causes ortho cyclization.
