Catalytic Stereospecific Allyl–Allyl Cross-Coupling of Internal Allyl Electrophiles with AllylB(pin)
摘要:
Application of internal electrophiles in catalytic stereospecific allyl allyl cross-coupling enable the rapid construction of multisubstituted 1,5-dienes, including those with all carbon quaternary centers. Compounds with minimal steric differentiation can be synthesized with high enantiomeric excess.
A new and general one-pot synthesis of propargyl alcohols from esters
作者:Min Jung Chae、Ah Ram Jeon、Tom Livinghouse、Duk Keun An
DOI:10.1039/c0cc04597g
日期:——
Intermediates easily prepared by partial reduction of various esters with LDBBA as a reducing agent smoothly react with lithium acetylides to give propargylalcohols, without isolation of partial reduction intermediates, in good yields (73-83%).
Access to Highly Functionalized Cyclopentenones via Diastereoselective Pauson–Khand Reaction of Siloxy-Tethered 1,7-Enynes
作者:Austin G. Gallagher、Huan Tian、Osmar A. Torres-Herrera、Shuai Yin、Anxin Xie、Daniel M. Lange、Jerica K. Wilson、Louis G. Mueller、Michael R. Gau、Patrick J. Carroll、Dionicio Martinez-Solorio
DOI:10.1021/acs.orglett.9b03255
日期:2019.11.1
Pauson–Khand reaction (PKR) of siloxy-tethered 1,7-enynes for the synthesis of cyclopentaoxasilinones has been developed. This transformation can be performed on a multigram scale and is characterized by a broad substrate scope, functional group compatibility, and high chemo- and diastereoselectivity. Oxidation of the resulting cyclopentaoxasilinones delivers stereoenriched β-alkylated cyclopentenones, which
Gold(I)-Catalyzed Rearrangement of Propargyl Benzyl Ethers: A Practical Method for the Generation and in Situ Transformation of Substituted Allenes
作者:Benoit Bolte、Yann Odabachian、Fabien Gagosz
DOI:10.1021/ja1020469
日期:2010.6.2
of benzyl propargyl ethers react with a gold(I) catalyst to furnish variously substituted allenes via a 1,5-hydride shift/fragmentation sequence. This transformation is rapid and practical. It can be performed under very mild conditions (room temperature or 60 degrees C) using terminal as well as substituted alkyne substrates bearing a primary, secondary, or tertiary benzyl ether group. The allenes
Neighboring Carbonyl Group Assisted Hydration of Unsymmetrical Aryl Alkynes Overriding Regular Selectivity
作者:Kishor L. Mendhekar、Tapas R. Pradhan、N. Arjunreddy Mallampudi、Debendra K. Mohapatra
DOI:10.1002/ejoc.201900941
日期:2019.9.8
A mild and highly regioselective gold‐catalyzed hydration of γ‐acetoxy aryl alkynes leading to anti‐Markovnikov products by the assistance of a neighboringcarbonylgroup is presented.
The first manganese-catalyzed hydroboration of propargylic alcohols and amines as well as internal alkynes is reported. High regio- and stereoselectivity is achieved by applying 2 mol % of a manganese precatalyst based on the readily accessible bis(imino)pyridine ligand and MnCl2 as metal source. Propargylic alcohols and amines, as well as symmetric internal alkynes, were efficiently converted into