24826-68-4Relevant academic research and scientific papers
Catalytic Multisite-Selective Acetoxylation Reactions at sp2 vs sp3 C-H Bonds in Cyclic Olefins
Zang, Zhong-Lin,Zhao, Sheng,Karnakanti, Shuklachary,Liu, Cheng-Lin,Shao, Pan-Lin,He, Yun
, p. 5014 - 5017 (2016/10/14)
The first Pd-catalyzed multisite-selective acetoxylation reactions are disclosed at an unactivated alkene sp2 C-H bond versus secondary allylic sp3 C-H bond in cyclic olefins via the modulation of directing groups. The different directing groups overcome the key challenge in differentiating C-H bonds and provide a new controlling approach for site-specific C-H activation. A wide variety of substrates are readily acetoxylated under operationally simple conditions. Mechanistic studies suggest that different Pd (IV) intermediates were involved in the multisite-selective acetoxylation reactions.
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.
AlEt3-promoted eliminative ring-opening of β-hydroxy epoxides: Highly stereoselective synthesis of terminal α-hydroxy olefins
Wang, Fei,Wang, Shao Hua,Tu, Yong Qiang,Ren, Shi Kuo
, p. 2189 - 2193 (2007/10/03)
AlEt3-promoted eliminative ring-opening of β-epoxy alcohols leading to α-hydroxy olefins is reported. This eliminative ring-opening reaction is shown to be highly stereoselective, thus providing an alternative asymmetric synthesis for α-hydroxy olefins.
The synthesis of mono- and bicyclic ethers via acid catalysed ring-opening cyclisation of tetrahydropyranyl ether derivatives
Dixon, Darren J.,Ley, Steven V.,Tate, Edward W.
, p. 1829 - 1836 (2007/10/03)
The synthesis of mono- and bicyclic ethers via acid catalysed ring-opening cyclisation of tetrahydropyranol ether derivatives was discussed. The products ring-opening cyclisation were hydrogenated in excellent yield and good to excellent diastereoselectiv
One-Pot Synthesis of Substituted Homoallylic Alcohols (3-Alkenols) and 1-Deuterio-3-alkenols; II. Extension to Ketone Enolates
Barluenga, Jose,Alvarez, Flora,Concellon, Jose M.,Bernad, Pablo,Yus, Miguel
, p. 318 - 320 (2007/10/02)
The reaction of different lithium ketone enolates with α-chloro carbonyl compounds followed by in situ reduction with lithium aluminium hydride or deuteride and final lithiation with lithium powder leads to the corresponding homoallylic or 1-deuterio homoallylic alcohols in a regioselective manner.
DIMETHYLALUMINUM CHLORIDE CATALYZED ENE REACTIONS OF ALDEHYDES.
Snider,Rodini,Kirk,Cordova
, p. 555 - 563 (2007/10/02)
Dimethylaluminum chloride, which is a mild Lewis acid and a proton scavenger, catalyzes the ene reactions of aliphatic and aromatic aldehydes with alkenes containing a disubstituted vinylic carbon. Proton-initiated rearrangements do not occur, since the alcohol-Lewis acid complex formed in the ene reaction reacts rapidly to give methane and a nonacidic aluminum alkoxide. Formaldehyde and excess Me//2AlCl give good yields of ene adducts with all types of alkenes. With 1 equiv of Me//2AlCl, formaldehyde and mono- and 1,2-disubstituted alkenes give gamma -chloro alcohols resulting from cis addition of chlorine and hydroxymethyl groups to the double bond. This work is pertinent to the synthesis of alcohols.
Diaklylaluminum chloride catalyzed ene reactions of aldehydes. Synthesis of ipsenol
Snider, Barry B.,Rodini, David J.
, p. 1815 - 1818 (2007/10/02)
Dimethylaluminum chloride which is a mild Lewis acid and a proton scavenger, catalyzes the ene reactions of aliphatic and aromatic aldehydes. Proton initiated rearrangements do not occur, since the alcohol-Lewis acid complex formed in the ene reaction rapidly to give methane and a non-acidic aluminum alkoxide.
