Synthesis of Vinyl-, Allyl-, and 2-Boryl Allylboronates via a Highly Selective Copper-Catalyzed Borylation of Propargylic Alcohols
作者:Lujia Mao、Rüdiger Bertermann、Katharina Emmert、Kálmán J. Szabó、Todd B. Marder
DOI:10.1021/acs.orglett.7b03294
日期:2017.12.15
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
Alkynylation of Aldehydes and Ketones Using the Bu<sub>4</sub>NOH/H<sub>2</sub>O/DMSO Catalytic Composition: A Wide-Scope Methodology
作者:Elena Yu. Schmidt、Natalia A. Cherimichkina、Ivan A. Bidusenko、Nadezhda I. Protzuk、Boris A. Trofimov
DOI:10.1002/ejoc.201402275
日期:2014.7
Favorsky reaction of a wide range of aldehydes and ketones with alkynes has been implemented under mild conditions (5–20 °C). Using a Bu4NOH/H2O/DMSO catalytic system, propargylic alcohols are formed cleanly in 39–93 % (mostly 72–93 %) yields and with ca. 100 % selectivity. The method is suitable for aliphatic, aromatic, and heteroaromatic aldehydes and ketones, and for aliphatic, aromatic, and functionalized
A direct and selective synthesis of α,β-unsaturated piperidones by a new palladium-catalyzed cascade carbonylation is described. In the presented protocol, easily available propargylic alcohols react with aliphatic amines to provide a broad variety of interesting heterocycles. Key to the success of this transformation is a remarkable catalytic cleavage of the present carbon–carbon triple bond by using
Silver(I)-Catalyzed Hydroazidation of Ethynyl Carbinols: Synthesis of 2-Azidoallyl Alcohols
作者:Zhenhua Liu、Jianquan Liu、Lin Zhang、Peiqiu Liao、Jinna Song、Xihe Bi
DOI:10.1002/anie.201310264
日期:2014.5.19
The hydroazidation of alkynes is the most straightforward pathway to synthetically useful vinyl azides. However, a general hydroazidation of alkynes remains elusive. Herein, a chemo‐ and regioselective transformation of ethynylcarbinols into vinyl azides is described. This reaction produces a wide variety of 2‐azidoallyl alcohols with high efficiency and in good to excellent yields. These compounds
Lewis and Brønsted Acid Cocatalyzed Reductive Deoxyallenylation of Propargylic Alcohols with 2-Nitrobenzenesulfonylhydrazide
作者:Zhaohong Liu、Peiqiu Liao、Xihe Bi
DOI:10.1002/chem.201404692
日期:2014.12.22
Reductivedeoxyallenylation of sterically hindered tertiary propargylicalcohols was realized on reaction with 2‐nitrobenzenesulfonylhydrazide (NBSH) by the combined use of Lewis and Brønstedacid catalysts. This method features a broad substrate scope, mild reaction conditions, and good functional‐group tolerance, and affords various mono‐, di‐, and trisubstituted allenes in good‐to‐excellent yields