Studies on Pd(II)-Catalyzed Coupling−Cyclization of α- or β-Amino Allenes with Allylic Halides
摘要:
The palladium-catalyzed coupling-cyclization of alpha- or beta-amino allenes with allylic halides leading to 3-allylic 2,5-dihydropyrroles and 1,2,3,6-tetrahydropyridines, respectively, was studied. The starting materials are easily available. The skeletons of both two classes of products were established by the X-ray diffraction studies of 7i and 9b. Through the study of the reaction of 2b with 3-chloro-1-butene, 1-chloro-2-butene, and pi-allyl palladium species and the stereochemical outcome of the coupling cyclization of (S)-2m and (R)-2n, it is believed that the current transformation most likely proceeded via a Pd(II)-catalyzed pathway, although a Pd(0) pathway cannot be completely excluded.
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
A Highly Efficient Preparative Method of α-Ylidene-β-Diketones via Au<sup>III</sup>-Catalyzed Acyl Migration of Propargylic Esters
作者:Shaozhong Wang、Liming Zhang
DOI:10.1021/ja062777j
日期:2006.7.1
A highlyefficient synthesis of α-alkylidene or benzylidene-β-diketones from readily available propargylic esters has been developed. The proposed key transformation is a novel intramolecular acyl migration to nucleophilic AuIII−C(sp2) bonds. Noteworthy features of this method are its efficiency and stereoselectivity. The yields of this reaction were mostly close to quantitative, and high to excellent
Ruthenium-Catalyzed [2 + 2] Cycloadditions between Norbornene and Propargylic Alcohols or Their Derivatives
作者:Gavin C. Tsui、Karine Villeneuve、Emily Carlson、William Tam
DOI:10.1021/om500563h
日期:2014.7.28
Diastereoselective ruthenium-catalyzed [2 + 2] cycloadditions of norbornene and propargylic alcohols or their derivatives were investigated. The cycloadditions were found to be highly stereoselective, giving exo cycloadducts in moderate to excellent yields with diastereoselectivities up to 92:8. When a chiral propargylic alcohol was used in the cycloaddition, up to 80% ee of the [2 + 2] cycloadducts was
In Situ Generation of Nucleophilic Allenes by the Gold-Catalyzed Rearrangement of Propargylic Esters for the Highly Diastereoselective Formation of Intermolecular C(sp<sup>3</sup>)C(sp<sup>2</sup>) Bonds
作者:Yang Yu、Weibo Yang、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/anie.201302402
日期:2013.7.15
particular for the synthesis of isochromane derivatives (see scheme), are provided by the title reaction. Excellent diastereoselectivites are achieved in this reaction which proceeds through a gold‐catalyzed 1,3‐acyloxy migration. In some cases exclusively the Z isomer is detected.
Atom-Economical Cross-Coupling of Internal and Terminal Alkynes to Access 1,3-Enynes
作者:Mingyu Liu、Tianhua Tang、Omar Apolinar、Rei Matsuura、Carl A. Busacca、Bo Qu、Daniel R. Fandrick、Olga V. Zatolochnaya、Chris H. Senanayake、Jinhua J. Song、Keary M. Engle
DOI:10.1021/jacs.0c12565
日期:2021.3.17
synthesizing 1,3-enynes without prefunctionalized building blocks. In this transformation several classes of unactivated internal acceptor alkynes can be coupled with terminal donor alkynes to deliver 1,3-enynes in a highly regio- and stereoselective manner. The scope of compatible acceptor alkynes includes propargyl alcohols, (homo)propargyl amine derivatives, and (homo)propargyl carboxamides. This method is