1667-00-1Relevant articles and documents
The Question of Cyclic Versus Acyclic Ions: The Structure of +. Gas Phase Ions
Dass, Chhabil,Gross, Michael L.
, p. 34 - 40 (1985)
The extent of isomerization of acyclic and cyclic gas phase radical cations of composition +. has been investigated by using collisionally activated dissociation spectroscopy.Both electron and charge exchange ionization were employed to form the ions with various internal energies.The +. ions investigated consisted of ionized phenylbutenes, ring-substituted methyl derivatives of allylbenzene and phenylpropene, 1-methyl-isopropenylbenzene, benzylcyclopropane, phenylcyclobutane, tetralin and 1-methylindan.The 1-methylindan and tetralin radical cations are the most stable of the C10H12 isomeric radical ions.The +. formed from acyclic olefins having the double bond in conjugation with the aromatic ring retain the initial structure to a significant extent.However, ions derived from olefins with the double bond out of conjugation with the benzene ring preferentially cyclize to stable five- and six-membered cyclic ions.Ring opening of small-ring cyclic ions, such as ionized benzylcyclopropane and phenylcyclobutane, occurs, followed by ring closure to the tetralin radical cation.
Nickel-catalyzed reductive deoxygenation of diverse C-O bond-bearing functional groups
Cook, Adam,MacLean, Haydn,St. Onge, Piers,Newman, Stephen G.
, p. 13337 - 13347 (2021/11/20)
We report a catalytic method for the direct deoxygenation of various C-O bond-containing functional groups. Using a Ni(II) pre-catalyst and silane reducing agent, alcohols, epoxides, and ethers are reduced to the corresponding alkane. Unsaturated species including aldehydes and ketones are also deoxygenated via initial formation of an intermediate silylated alcohol. The reaction is chemoselective for C(sp3)-O bonds, leaving amines, anilines, aryl ethers, alkenes, and nitrogen-containing heterocycles untouched. Applications toward catalytic deuteration, benzyl ether deprotection, and the valorization of biomass-derived feedstocks demonstrate some of the practical aspects of this methodology.
Asymmetric Photocatalytic C-H Functionalization of Toluene and Derivatives
Mazzarella, Daniele,Crisenza, Giacomo E. M.,Melchiorre, Paolo
supporting information, p. 8439 - 8443 (2018/07/25)
Reported herein is a visible-light-mediated organocatalytic direct C-H functionalization of toluene derivatives to afford enantioenriched β-benzylated aldehydes from the corresponding enals. The process combines the oxidative power of a chiral excited-state iminium ion and the basic nature of its counteranion to trigger the generation of benzylic radicals by means of a sequential multisite proton-coupled electron transfer mechanism. This study shows that feedstock chemicals generally used as solvents, such as toluene and xylene derivatives, can be used as substrates for making chiral molecules with high enantioselectivity.