Regioselective Rh-Catalyzed Hydroformylation of 1,1,3-Trisubstituted Allenes Using BisDiazaPhos Ligand
作者:Josephine Eshon、Clark R. Landis、Jennifer M. Schomaker
DOI:10.1021/acs.joc.7b01140
日期:2017.9.15
The efficient hydroformylation of 1,1,3-trisubstituted allenes is accomplished with low loadings of a Rh catalyst supported by a BisDiazaPhos (BDP) ligand. The ligand identity is key to achieving high regioselectivity, while the mild reaction conditions minimize competing isomerization and hydrogenation to produce β,γ-unsaturated aldehydes and their derivatives in excellent yields.
Au(PPh3)Cl–AgSbF6-catalyzed rearrangement of propargylic 1,3-dithianes: formation of 8-membered 1,3-bisthio-substituted cyclic allenes
作者:Xia Zhao、Zhenzhen Zhong、Lingling Peng、Wenxiong Zhang、Jianbo Wang
DOI:10.1039/b903028j
日期:——
Au(PPh(3))Cl-AgSbF(6)-catalyzed rearrangement of propargylic 1,3-dithiane leads to the formation of 8-membered dithio-substituted cyclic allenes, which are remarkably stable.
Rhodium-Catalyzed Isomerization of α-Arylpropargyl Alcohols to Indanones: Involvement of an Unexpected Reaction Cascade
作者:Ryo Shintani、Kazuhiro Okamoto、Tamio Hayashi
DOI:10.1021/ja042582g
日期:2005.3.9
alkynes + aromatic aldehydes), this method provides a new way of constructing indanones with high efficiency. By the mechanistic investigations using deuterium-labeled substrates, it has also been demonstrated that the reaction goes through an unexpected cascade, with a 1,4-hydrogen shift being the turnover-limiting step of the catalytic cycle.
We describe herein a highly stereoselective access to Cbz-protected β-enaminones 2 based on the NaOH catalyzed rearrangement of propargylichydroxylamines 1. The synthetic potential of these β-enaminones is illustrated in an original synthesis of pyrimidines.
The use N‐sulfonyl‐protected hydroxylamines as bi‐nucleophiles in iron‐catalyzed propargylic substitutions allows the selective one‐potsynthesis of four classes of substituted isoxazoles or isoxazolines from the same propargylic alcohols (21 examples) by simply tuning the nature of the base. By using an iron(III) catalyst and a base such as triethylamine (3 equiv), isoxazoles 3 are obtained in good