Palladium-Catalyzed meta-C–H Olefination of Arene-Tethered Diols Directed by Well-Designed Pyrimidine-Based Group
摘要:
The palladium-catalyzed meta-olefination of arene-tethered diols attached to a well-designed pyrimidine moiety is presented. Applications of the protocol are illustrated by the synthesis of various diol-based natural products, such as coumarins, phenylpropanoids, stilbenes, and chalcones. Advantages of this method are demonstrated through the easy removal of the template and a gram-scale olefination reaction. Finally, experimental verification, including H-1 NMR, ESI-MS and IR, and DFT studies are undertaken to elucidate the mechanistic complexity.
A palladium-catalyzedoxidativeallylation of bis[(pinacolato)boryl]methane to afford the corresponding homoallylic organoboronic esters with moderate to excellent yields is reported. This novel transformation provides an efficient strategy for the construction of homoallylic organoboronic esters in one step with a broad substrate scope. It is proposed that the palladium-catalyzedoxidative allylic
Novel electron-transfer-induced intermolecular [2 + 2] cycloaddition reactions between an aliphatic cyclic enol ether and several unactivated olefins have been demonstrated on the basis of the aromatic “redox tag” strategy. The aromatic “redox tag” was oxidized during the formation of the cyclobutane ring, affording the relatively long-lived aromatic radical cation, which was then reduced to complete
Palladium-Catalyzed Regioselective Allylation of Chloromethyl(hetero)arenes with Allyl Pinacolborate
作者:Sheng Zhang、Aziz Ullah、Yoshinori Yamamoto、Ming Bao
DOI:10.1002/adsc.201700350
日期:2017.8.17
The palladium-catalyzed regioselective allylation reaction between chloromethyl(hetero)arenes and allyl pinacolborate is reported in this work. Chloromethylarenes smoothly reacted with allyl pinacolborate, producing para-allylated dearomatization products or para-allylated arenes in satisfactory to good yields. 2-(Chloromethyl)thiophenes and 2-(chloromethyl)furans bearing substituents on the 5-positions
Palladium-Catalyzed sp<sup>2</sup>–sp<sup>3</sup> Coupling of Chloromethylarenes with Allyltrimethoxysilane: Synthesis of Allyl Arenes
作者:Sheng Zhang、Jinfang Cai、Yoshinori Yamamoto、Ming Bao
DOI:10.1021/acs.joc.7b00678
日期:2017.6.2
Palladium-catalyzed remote sp2–sp3 coupling reaction of chloromethylarenes with allyltrimethoxysilane is described in this work. The allylation reaction regioselectively occurred on the para-positions of 1-(chloromethyl)naphthalenes and benzyl chlorides to form new C(sp2)–C(sp3) bonds. The reaction proceeds smoothly under mild conditions to produce allyl arenes in moderate to excellent yields.