Competition between Cyclization and Dehalogenation in the Photochemistry of Cinnamylphenols with Halogen Substituents at the Phenolic and Styrenic Chromophores
Synthesis of Enantioenriched 3,4-Disubstituted Chromans through Lewis Base Catalyzed Carbosulfenylation
作者:Travis Menard、Aragorn Laverny、Scott E. Denmark
DOI:10.1021/acs.joc.1c02290
日期:2021.11.5
carbosulfenylation of alkenes to construct 3,4-disubstituted chromans is described. Alkene activation proceeds through the intermediacy of enantioenriched, configurationally stable thiiranium ions generated from catalytic, Lewis base activation of an electrophilic sulfenylating agent. The transformation affords difficult-to-generate, enantioenriched, 3,4-disubstituted chromans in moderate to high yields and
Selective Synthesis of
<i>Z</i>
‐Cinnamyl Ethers and Cinnamyl Alcohols through Visible Light‐Promoted Photocatalytic
<i>E</i>
to
<i>Z</i>
Isomerization
A photocatalytic E to Z isomerization of alkenes using an iridium photosensitizer under mild reaction conditions is disclosed. This method provides scalable and efficient access to Z-cinnamyl ether and allylic alcohol derivatives in high yields with excellent stereoselectivity. Importantly, this method also provides a powerful strategy for the selective synthesis of Z-magnolol and honokiol derivatives
Synthesis and structure of [Ru(PPh3)2(bipy)(MeCN)Cl][BPh4] and it's catalytic property towards regioselective and stereoselective allylation of phenols
The compound, [Ru(PPh3)2(bipy)(MeCN)Cl][BPh4] (1) has been synthesized from the precursor complex, [Ru(bipy)(PPh3)2Cl2]. The complex has been structurally characterized. This complex has been found to be an efficient catalyst for the regioselective allylation of phenols.
Regio- and Enantioselective Iridium-Catalyzed Intermolecular Allylic Etherification of Achiral Allylic Carbonates with Phenoxides
作者:Fernando López、Toshimichi Ohmura、John F. Hartwig
DOI:10.1021/ja029790y
日期:2003.3.1
An enantioselective and regioselective iridium-catalyzed allylic etherification is described. The reaction of sodium and lithium aryloxides with achiral (E)-cinnamyl and terminal aliphatic allylic electrophiles in the presence of 2 mol % of an iridium-phosphoramidite complex provides chiral allylic aryl ethers in high yields and excellent levels of regio- and enantioselectivity. Lithium aryloxides
Polymeric β-alanine incarcerated Pd(<scp>ii</scp>) catalyzed allylic etherification in water: a mild and efficient method for the formation of C(sp<sup>3</sup>)–O bonds
作者:Mita Halder、Md. Mominul Islam、Sabir Ahammed、Sk. Manirul Islam
DOI:10.1039/c5ra26182a
日期:——
polystyrene and β-alanine. Using this polymer incarcerated palladium(II) catalyst a useful and efficient procedure for stereospecific synthesis of allyl-aryl ethers has been developed. The benzylic, aromatic, and heteroaromatic phenols react with various substituted allyl acetates by this procedure to furnish a library of allyl-aryl and allyl-hetero-aryl ethers in high yields. The catalyst could be recovered