Mizoroki–Heck reaction of 1,2-disubstituted aryl alkenes: Variables of synthesis, solvent and ligand modulation of reactivity
作者:Pronnoy G. Bangar、Priyanka R. Jawalkar、Swapnil R. Dumbre、Pallavi K. Raut、Dharmaraj J. Patil、Neethu Tv、Shana Sudhakaran、Suresh Iyer
DOI:10.1080/00397911.2020.1811986
日期:2020.12.16
Abstract Reaction of aryl iodides with 1,2-disubstituted aryl alkenes in the presence of TBABr/TBACl gave high yields of the Mizoroki–Heck product. Phosphine ligands were used for the modulation of reactivity and stereoselectivity, for the reaction of 4-iodoanisole with cinnamaldehyde. tert-Bu3P.HBF4 gave the highest E:Z ratio of 1:0.08. The use of PEG-200 and PEG-400 as solvent could activate the
A highly selective cobalt-catalyzed single and double dehydrogenative borylations (DHBs) of terminal alkenes have been developed for the synthesis of trans-monoborylalkenes and diborylalkenes, respectively. While the cobalt-catalyzed double DHBs of aryl 1-alkenes with 2 equiv of bis(pinacolato)diboron (B2pin2) in the presence of 1 equiv of CsF in DMF produce 1,1-diborylalkenes selectively, the double
and dioxygen serve as oxidants in highly stereoselective oxidative Pd‐catalyzed Heck arylations in which aryl boronicacids are used to synthesize triarylalkyl‐substituted olefins. The reactions occur under very mild conditions at room temperature. As an example, the threefold sequential arylation of methyl acrylate is the crucial step in the stereoselective synthesis of Z‐Tamoxifen.
carbofunctionalization of internal alkynes has been established herein. This method proceeds through a formal anti-carbopalladation, forming trans-alkenyl palladium species, which was trapped by aryl boronic acids to provide all-carbon tetrasubstituted alkenes in 32–92% yields. The trans-selective arylsilylation/remote C–H silylation and hydroarylation/remote C–H borylation of internal alkynes were also achieved using