Synthesis of Functionalized Epoxides by Copper-Catalyzed Alkylative Epoxidation of Allylic Alcohols with Alkyl Nitriles
作者:Ala Bunescu、Qian Wang、Jieping Zhu
DOI:10.1021/acs.orglett.5b00571
日期:2015.4.17
A copper-catalyzed oxyalkylation of allylic alcohols using nonactivated alkyl nitriles as reaction partners was developed. A sequence involving generation of an alkyl nitrile radical followed by its addition to a double bond and a copper-mediated formation of C(sp3)–O bond was proposed to account for the reaction outcome. The protocol provided an efficient route to functionalized tri- and tetrasubstituted
The reactions of trialkylstannylmethyllithium with α,β-epoxyketones afforded mainly cyclopropanols, while α-chloro ketones afforded allyl alcohols and/or cyclopropanols, in varying amounts depending upon the molar ratio of the reagent to the substrate.
Why is cis / trans stereoinversion with Li + (THF) 4 migration across the phenyl ring of α-lithiostyrene accelerated by two ortho -methyl groups?
作者:Rudolf Knorr、Ernst Lattke、Jakob Ruhdorfer、Kathrin Ferchland、Ulrich von Roman
DOI:10.1016/j.tet.2018.01.047
日期:2018.4
Common wisdom might anticipate that two methyl groups placed on a molecular migration route should act as an impediment. However, the “conductedtour” migration of Li+(THF)4 across the aryl ring (“π-route”) during the cis/trans stereoinversion of α-arylvinyllithiums had been found to occur with practically equal velocities in the presence of either one or two ortho-alkyl substituents. We now report
Intermolecular Heck Coupling with Hindered Alkenes Directed by Potassium Carboxylates
作者:Tucker R. Huffman、Yebin Wu、Alexis Emmerich、Ryan A. Shenvi
DOI:10.1002/anie.201813233
日期:2019.2.18
Pd0 -catalyzed Mizoroki-Heck reactions traditionally exhibit poor reactivity with polysubstituted, unbiased alkenes. Intermolecular reactions with simple, all-carbon tetrasubstituted alkenes are unprecedented. Herein we report that pendant carboxylic acids, combined with bulky monophospine ligands on palladium, can direct the arylation of tri- and tetrasubstituted olefins. Quaternary carbons are established
Selenium stabilized carbanions. .alpha.-Lithio selenoxides as reagents for the synthesis of olefins, allyl alcohols, and dienes
作者:Hans J. Reich、Shrenik K. Shah、Flora Chow
DOI:10.1021/ja00516a026
日期:1979.10
Techniques for the preparation of a-lithio selenoxides have been developed. These reagents react cleanly with most aldehydes and ketones to give 0-hydroxy selenoxides, which can be thermolyzed to allyl alcohols or reduced to hI result of the limited acidifying power of the phenylseleno group, and the propensity of selenides to be fragmented upon treatment with powerful metalating agents. The substantially