Copper(I)-Catalyzed Regio- and Stereoselective Intramolecular Alkylboration of Propargyl Ethers and Amines
作者:Hiroaki Iwamoto、Yu Ozawa、Koji Kubota、Hajime Ito
DOI:10.1021/acs.joc.7b02071
日期:2017.10.6
transformed into multisubstituted alkenes through stereospecific transformations. Mechanistic studies showed that the chemo- and stereoselectivity of copper(I)-catalyzed borylation depends on the type of leaving group. Density functional theory calculations suggested that the regioselectivity of the borylcupration of the alkyne is controlled by the electronic effect of the oxygen atom of the propargyl ether
The Boron-Wittig Olefination of Aldehydes and Ketones with Bis[(pinacolato)boryl]methane: an Extended Reaction Scope
作者:Maksym Kovalenko、Dmytro V. Yarmoliuk、Dmytro Serhiichuk、Daria Chernenko、Vladyslav Smyrnov、Artur Breslavskyi、Oleksandr V. Hryshchuk、Ihor Kleban、Yuliya Rassukana、Andriy V. Tymtsunik、Andrey A. Tolmachev、Yuliya O. Kuchkovska、Oleksandr O. Grygorenko
DOI:10.1002/ejoc.201900648
日期:2019.9.8
The boron‐Wittig olefination of aliphatic and aromaticketones and aldehydes with bis[(pinacolato)boryl]methane is described. The 2,2‐disubstituted and 2‐monosubstituted alkenylboronic acid esters were obtained on a multigram scale with 35–90 % yield.
Rhodium catalysed dehydrogenative borylation of vinylarenes and 1,1-disubstituted alkenes without sacrificial hydrogenation—a route to 1,1-disubstituted vinylboronates
作者:R. Benjamin Coapes、Fabio E. S. Souza、Rhodri Ll. Thomas、Jonathan J. Hall、Todd B. Marder
DOI:10.1039/b211789d
日期:2003.2.20
The complex trans-[Rh(Cl)(CO)(PPh3)2] (1) is an efficient catalyst precursor for the dehydrogenative borylation of alkenes without consumption of half the alkene substrate by hydrogenation, giving useful vinylboronate esters including 1,1-disubstituted derviatives that cannot be made by alkyne hydroboration.
The carboboration of terminal alkynes was studied with a N‐heterocyclic carbene‐capped α‐cyclodextrin copper(I) complex as catalyst. The intermolecular reaction with CH3I gave linear (L) vinyl boron isomers with high selectivity. The intramolecular reaction with terminal alkynes led to exocyclic vinyl boronates and to an unexpected endocyclic (Z)‐isomer, suggesting an unusual mechanism promoted by
Synthesis of Functionalized Vinyl Boronates via Ruthenium-Catalyzed Olefin Cross-Metathesis and Subsequent Conversion to Vinyl Halides
作者:Christie Morrill、Robert H. Grubbs
DOI:10.1021/jo0345345
日期:2003.7.1
using ruthenium-catalyzed olefin cross-metathesis of 1-propenyl pinacol boronate and various alkenes, including functionalized and 1,1-disubstituted alkenes. The resultant boronate cross products are stereoselectively transformed into predominantly Z-vinyl bromides and E-vinyl iodides. The vinyl bromides may be synthesized in a two-step, one-pot synthesis from a variety of olefins, resulting in a Z-selective