A Novel Approach for the Formation of Carbon−Nitrogen Bonds: Azidation of Alkyl Radicals with Sulfonyl Azides
作者:Cyril Ollivier、Philippe Renaud
DOI:10.1021/ja004129k
日期:2001.5.1
Two preparatively attractive methods for the azidation of alkyl radicals are described. Secondary and tertiary alkyl iodides and dithiocarbonates are easily converted into the corresponding azides, either by reaction with ethanesulfonyl azide in the presence of dilauroyl peroxide, or by treatment with benzenesulfonyl azide and hexabutylditin in the presence of a radical initiator. Interestingly, intramolecular
Single-Electron-Transfer Strategy for Reductive Radical Cyclization: Fe(CO)<sub>5</sub> and Phenanthroline System
作者:Joon Young Hwang、Jong Hwa Baek、Tae Il Shin、Jung Ha Shin、Jae Won Oh、Kwang Pyo Kim、Youngmin You、Eun Joo Kang
DOI:10.1021/acs.orglett.6b02375
日期:2016.10.7
electron-transfer strategy using low-valent iron pentacarbonyl [Fe(CO)5] to generate radical species from alkyl iodides was achieved. A range of pyrrolidines, tetrahydrofurans, and carbocycles were synthesized via 5-exo cyclization reactions of alkyl radical intermediates generated by electron transfer from a system involving Fe(CO)5, 1,10-phenanthroline, and diisopropylamine. Moreover, tandem addition
Treatment of various organic halides with phosphinic acid (hypophosphorous acid) in aqueous ethanol in the presence of a radical initiator and a base gave the corresponding reduced products in high yields. Addition of a base is indispensable for the reduction of halides by phosphinic acid. Allylic ether of o-iodophenol or 2-haloalkanal allylic acetal underwent radical cyclization under the same conditions
A nickel‐catalyzed three‐component reaction involving terminal alkynes, boronic acids, and alkyl halides is presented herein. Trisubstituted alkenes can be obtained in a highly regio‐ and stereocontrolled manner by the simultaneous addition of both aryl and alkylgroups across the triple bond in a radical‐mediated process. The reaction, devoid of air‐ and moisture‐sensitive organometallic reagents
iodoalkanes with PhSiH3 in THF at 70 °C gave dehalogenated alkanes in good to high yields. In the presence of Et3B and air, the reduction proceeded smoothly at 30 °C. When 2,6-lutidine and air were used as additives, the In(OAc)3-catalyzed system enabled an efficient reduction of simple and functionalized iodoalkanes in EtOH. Catalytic use of GaCl3 was found to be effective in the reduction of haloalkanes