Palladium(0)-Catalyzed Cross-Coupling of 1,1-Diboronates with Vinyl Bromides and 1,1-Dibromoalkenes
作者:Huan Li、Zhikun Zhang、Xianghang Shangguan、Shan Huang、Jun Chen、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201407000
日期:2014.10.27
Palladium‐catalyzed cross‐coupling reactions of 1,1‐diboronates with vinylbromides and dibromoalkenes were found to afford 1,4‐dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1‐diboronates and allylboron intermediates generated in the initial coupling.
Assembly of Tetrahydroquinolines and 2-Benzazepines by Pd-Catalyzed Cycloadditions Involving the Activation of C(sp<sup>3</sup>)–H Bonds
作者:Xandro Vidal、José Luis Mascareñas、Moisés Gulías
DOI:10.1021/acs.orglett.1c01594
日期:2021.7.16
Cycloadditionreactions are among the most practical strategies to assemble cyclic products; however, they usually require the presence of reactive functional groups in the reactants. Here, we report a palladium-catalyzed formal (4 + 2) cycloaddition that involves the activation of C(sp3)–H bonds and provides a direct, unconventional entry to tetrahydroquinoline skeletons. The reaction utilizes amidotolyl
Coupling of N-Tosylhydrazones with Terminal Alkynes Catalyzed by Copper(I): Synthesis of Trisubstituted Allenes
作者:Qing Xiao、Ying Xia、Huan Li、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201005741
日期:2011.2.1
The easy way to allenes: An operationally simple reaction under mild conditions has led to the direct formation of trisubstituted allenes (see scheme; Ts=4‐toluenesulfonyl). An unprecedented copper–carbene migratory insertion process seems to take place, in contrast to classic copper(I)‐catalyzed reactions of diazo compounds.
Copper-Catalyzed 1,1-Boroalkylation of Terminal Alkynes: Access to Alkenylboronates via a Three-Component Reaction
作者:Ziyong Li、Jiangtao Sun
DOI:10.1021/acs.orglett.1c01081
日期:2021.5.7
A copper-catalyzed three-component reaction of terminal alkynes, diazo compounds, and B2pin2 to prepare trisubstituted alkenylboronates has been developed. This difunctionalization of alkynes selectively occurs at the terminal carbon atom and proceeds via a tandem sequence. The copper catalyst plays dual roles in the whole process, namely, the initial copper-catalyzed cross-coupling and the following
allenylation, allylation, and annulation reactions. The outcome is governed by both the reactivity of the allene and the formation and stability of the organometallic intermediate. An efficient Rh(III)-catalyzed, weakly coordinating group-directed dienylation of electronically unbiased allenes is developed using an N-acyl amino acid as a ligand. Further elaboration of the dienylated products to construct