Highly E-Selective, Stereoconvergent Nickel-Catalyzed Suzuki–Miyaura Cross-Coupling of Alkenyl Ethers
摘要:
An improved method for the nickel-catalyzed Suzuki-Miyaura cross-coupling of alkenyl ethers is reported. This stereoconvergent protocol allows for the utilization of a wide range of alkenyl ethers and aryl boronic esters for the synthesis of variously substituted styrene derivatives. An olefinic mixture with respect to the alkenyl ethers can be employed, thereby circumventing the stereodefined synthesis of starting materials. Preliminary mechanistic investigations indicate a nickel-catalyzed olefin isomerization following initial stereoretentive cross-coupling.
Nickel- or palladium-catalyzed cross coupling. 31. Palladium- or nickel-catalyzed reactions of alkenylmetals with unsaturated organic halides as a selective route to arylated alkenes and conjugated dienes: scope, limitations, and mechanism
作者:Eiichi Negishi、Tamotsu Takahashi、Shigeru Baba、David E. Van Horn、Nobuhisa Okukado
DOI:10.1021/ja00242a024
日期:1987.4
Al, Zr, and Zn were 2, 3, and > 2000 mmol of (E)-1-octenylbenzene (8) per mmol of Pd(PPh/sub3/)/sub 4/ per hour at room temperature, respectively. The stoichiometric reaction of PhPd(PPh/sub3/)/sub 2/I (6) with 1.2 equiv of (E)-1-octenylzinc chloride (7) in a 2:1 mixture of CD/sub 2/Cl/sub2/ and THF was examined in detail. The reaction follows second-order kinetics (k/sub2/ = 2.9 L/(mol.min) at
General Copper-Catalyzed Coupling of Alkyl-, Aryl-, and Alkynylaluminum Reagents with Organohalides
作者:Bijay Shrestha、Surendra Thapa、Santosh K. Gurung、Ryan A. S. Pike、Ramesh Giri
DOI:10.1021/acs.joc.5b02077
日期:2016.2.5
We report the first example of a very general Cu-catalyzed cross-coupling of organoaluminum reagents with organohalides. The reactions proceed for the couplings of alkyl-, aryl-, and alkynylaluminum reagents with aryl and heteroarylhalides and vinyl bromides, affording the cross-coupled products in good to excellent yields. Both primary and secondary alkylaluminum reagents can be utilized as organometallic
Metal‐Catalyzed Remote Functionalization of ω‐Ene Unsaturated Ethers: Towards Functionalized Vinyl Species
作者:Guo‐Ming Ho、Lina Judkele、Jeffrey Bruffaerts、Ilan Marek
DOI:10.1002/anie.201802434
日期:2018.7.2
The combined ruthenium‐catalyzed chain walking with the nickel‐catalyzed cross‐coupling reaction of ω‐alkenyl ethers provide a unique entry to functionalized vinyl species. This transformation illustrates the power and flexibility of remote functionalization by demonstrating the compatibility of two independent reactions involving unrelated sites.
Platinum-catalyzed cross-couplings of organoboronic acids with aryl iodides
作者:Chang Ho Oh、Young Mook Lim、Choong Ho You
DOI:10.1016/s0040-4039(02)00863-8
日期:2002.5
Tetrakis(triphenylphosphine)platinum in DMF was utilized as a mild catalyst for cross-coupling reactions of organoboronicacids with aryliodides. The present reactions exhibited excellent group-selectivity where couplings of organoboronicacids 2a–e with 4-bromo-1-iodobenzene (4) give 4-arylbromobenzenes 5a–b and 4-alkenylbromobenzenes 5c–e in excellent yields.
n-pentyl 1-methyl-1H-tetrazol-5-yl (MT) sulfone 1a in the Julia-Kocienski reactions were compared with those of the PT sulfone 1b and the TBT sulfone 1c. The improved stability of the anion derived from the n-pentyl MT sulfone 1a enhanced the efficiency of the olefination reactions and gave higher yields of the product alkenes 3 compared with the PT sulfone 1b. Especially high E-selectivity and high