191403-24-4Relevant academic research and scientific papers
Dehydrogenative Meyer-Schuster-like rearrangement: A gold-catalyzed reaction generating an alkyne
Yu, Yang,Yang, Weibo,Pflaesterer, Daniel,Hashmi, A. Stephen K.
, p. 1144 - 1147 (2014)
Easily accessible propargylic esters are converted to the inverted alkynyl ketones in an oxidative gold-catalyzed reaction. Gagosz's catalyst in combination with PhI(OAc)2 is the best system for this conversion and 18 examples with yields up to 80 % are reported. The results indicate that the triple bond in the product is formed by elimination from a vinylgold intermediate. In a formal sense the new conversion overall is a dehydrogenative Meyer-Schuster rearrangement. It takes alkynes: Propargyl esters can be converted into alkynyl ketones by a new oxidative gold-catalyzed reaction. The best catalyst system is Ph3PAuCl/AgNTf2 in combination with the oxidant PhI(OAc)2. The yields are as high as 80 % and the reaction can be conducted in the presence of air. Copyright
Cadmium(II) Chloride-Catalyzed Dehydrative C?P Coupling of Propargyl Alcohols with Diarylphosphine Oxides to Afford Allenylphosphine Oxides
Yang, Jianlin,Zhang, Ming,Qiu, Kang,Wang, Lize,Yu, Jingjing,Xia, Zefeng,Shen, Ruwei,Han, Li-Biao
supporting information, p. 4417 - 4426 (2017/12/26)
The cadmium(II) chloride-catalyzed dehydrative C?P cross-coupling reaction of propargyl alcohols with diarylphosphine oxides is reported. Several propargyl alcohols including those bearing the sterically demanding tert-butyl group at the triple bond terminus can be used as good substrates in the reaction to produce the corresponding allenylphosphine oxides in good to high yields in acetonitrile at 100 °C. The reaction can also be easily scaled up to a gram-scale synthesis. A mechanism study indicates that the reaction may proceed through a process of propargylic substitution to generate phosphonite intermediates followed by [2,3] sigmatropic rearrangement to produce the allenyl products, rather than through a common allenylative substitution resulting from P-nucleophilicity. (Figure presented.).
Synthesis of Vinyl-, Allyl-, and 2-Boryl Allylboronates via a Highly Selective Copper-Catalyzed Borylation of Propargylic Alcohols
Mao, Lujia,Bertermann, Rüdiger,Emmert, Katharina,Szabó, Kálmán J.,Marder, Todd B.
supporting information, p. 6586 - 6589 (2017/12/26)
An efficient methodology for the synthesis of vinyl-, allyl-, and (E)-2-boryl allylboronates from propargylic alcohols via Cu-catalyzed borylation under mild conditions is reported. In the presence of commercially available Cu(OAc)2 or Cu(acac)2 and Xantphos, the reaction affords the desired products in up to 92% yield with a broad substrate scope (43 examples). Isolation of an allenyl boronate as the reaction intermediate suggests that an insertion-elimination-type reaction, followed by borylcupration, is involved in the borylation of propargylic alcohols.
