The metal-free oxidative alkene methylation/alkynylation of 1,4-enyn-3-ols with an organic peroxide as the methyl source has been developed, which provides straightforward and practical access to the challenging quaternary-carbon-containing but-3-yn-1-ones. The method is reasoned to go through methylation of functional alkenes utilizing dicumyl peroxide as the methylating reagent and subsequent intermolecular
Metal-Free Iodosulfonylation of Internal Alkynes: Stereodefined Access to Tetrasubstituted Olefins
作者:Ravi Kumar、Vikas Dwivedi、Maddi Sridhar Reddy
DOI:10.1002/adsc.201700576
日期:2017.8.17
The stereoselective E‐iodosulfonylation of internalalkynes for synthesizing highly defined tetrasubstituted olefins using sodium phenyl sulfinate and iodine has been achieved. Most of the alkynes explored are non‐symmetrical and the regioselection is under full control. Arylalkynes with various electron‐withdrawing groups like keto, aldehyde, ester, amide, cyano, sulfone, bromo, chloro and iodo on
3-exo-dig cyclization with 1,2-alkynyl migration of 1,4-enynes with simple cycloalkanes was established, enabling C–C breaking and reconstruction to access a wide range of α-alkynyl ketones with generally good yields by FeCl2/di-tert-butyl peroxide (DTBP) as a catalytic oxidation system. Radical-induced C(sp3)–H functionalization of cycloalkanes was realized, leading to the direct formation of C(sp3)–C(sp3)
one-pot approach for the synthesis of quinolines from o-aminothiophenol and 1,3-ynone under mild conditions is disclosed. With the aid of ESI-MS analysis and parallel experiments, a three-step mechanism is proposed-a two-step Michael addition-cyclization condensation step leading to intermediate 1,5-benzothiazepine catalyzed by zirconocene amino acid complex Cp2Zr(η1-C9H10NO2)2, followed by I2-mediated
A novel photoredox catalysis for multiple functionalization of two different types of unactivatedalkenes in a single operation was reported through a conceptually new mode of annulation-alkynyl migration. A wide array of cyclopentane carboxylates were synthesized in a highly selective and functional-group-compatible manner via C-centered radical induced cascade 5-exo-trig/5-exo-dig bicyclization and