A Mild Synthesis of Vinyl Halides and gem-Dihalides Using Triphenyl Phosphite−Halogen-Based Reagents
摘要:
A new application of (PhO)(3)P-halogen-based reagents to the synthesis of vinyl halides and gem-dihalides is described. Vinyl halides were prepared in good to excellent yields from enolizable ketones, whereas aldehydes afforded the corresponding gem-dihalides. The halogenation proceeded smoothly under mild conditions.
Chemoselective Homologation–Deoxygenation Strategy Enabling the Direct Conversion of Carbonyls into (<i>n+1</i>)-Halomethyl-Alkanes
作者:Margherita Miele、Andrea Citarella、Thierry Langer、Ernst Urban、Martin Zehl、Wolfgang Holzer、Laura Ielo、Vittorio Pace
DOI:10.1021/acs.orglett.0c02831
日期:2020.10.2
The sequential installation of a carbenoid and a hydride into a carbonyl, furnishing halomethyl alkyl derivatives, is reported. Despite the employment of carbenoids as nucleophiles in reactions with carbon-centered electrophiles, sp3-type alkyl halides remain elusive materials for selective one-carbon homologations. Our tactic levers on using carbonyls as starting materials and enables uniformly high
Alkyl Isobenzofurans from Phthalides; Inter and Intramolecular Diels-Alder Reactions
作者:Sanath K. Meegalla、Russell Rodrigo
DOI:10.1055/s-1989-27438
日期:——
A general procedure for the conversion of phthalides 1 to alkyl isobenzofurans 4 is described and illustrated with nine. examples. Thus, the alkylidene phthalans 3 produced from the phthalides 1 in one step are in acid catalyzed equilibrium with the. alkyl isobenzofurans 4 which are trapped in situ by dienophiles as the inter- and intramolecular Diels-Alder adducts 5-9.
hydrobromination of terminal and internal alkynes with a commercially available solution of hydrogen bromide in acetic acid has been investigated for regio- and stereoselectivesynthesis of bromoalkenes. Under an aerobic atmosphere at room temperature, the reaction of ethynylarenes with a small excess of HBr efficiently gave (2-bromoethenyl)arenes with good to high E-selectivity. (Alk-1-ynyl)arenes, or internal
Treatment of trimethylsilyl esters with a reagent for alkylidenation of carbonyl groups derived from 1,1-dibromoalkane, zinc, TiCl4, and TMEDA in THF gives Z-trimethylsilyl enol ethers in a regio- and stereoselective manner.
Oxidative deamination of primary amines: selective synthesis of geminal dihalides
作者:Michael P. Doyle、Bernard Siegfried
DOI:10.1039/c39760000433
日期:——
Oxidativedeamination of unbranched primaryamines by the combination of alkyl nitrites and anhydrous copper(II) halides in acetonitrile produces geminal dihalides selectively and in synthetically useful yields.