photoredox catalysis. Mechanistic studies suggest that the observed selectivity was due to different active states of Ni(I) and Ni(0) modulated by Ru- and Ir-based photoredox catalysts, respectively. The ability to access different organometallic oxidation states via photoredox catalysis promises to inspire new perspectives for synergistic transition-metal-catalyzed divergent synthesis.
Mechanistic Investigation of a Novel Vitamin B<sub>12</sub>-Catalyzed Carbon−Carbon Bond Forming Reaction, the Reductive Dimerization of Arylalkenes
作者:Justin Shey、Chris M. McGinley、Kevin M. McCauley、Anthony S. Dearth、Brian T. Young、Wilfred A. van der Donk
DOI:10.1021/jo0160470
日期:2002.2.1
reaction to the active Co(I) state, and by removing Co(II) it also prevents the nonproductive recombination of alkyl radicals with cob(II)alamin. The mechanism of the formation of benzylic radicals from arylalkenes and cob(I)alamin poses an interesting problem. The results with a one-electron transfer probe indicate that radical generation is not likely to involve an electrontransfer. Several alternative
A highly efficient Co-catalyzed enantioselective alkylation of alkenes with indoles, thiophenes and electron rich arenes has been developed. This is the first CoH-catalyzed asymmetric hydrofunctionalization using carbon nucleophiles via hydrogen atom transfer.
Hydrogen Transfer. V.<sup>1</sup> Reaction of m-Cymene and o-Cymene with Methylcyclohexene in the Presence of Hydrogen Fluoride
作者:Herman Pines、D. R. Strehlau、V. N. Ipatieff
DOI:10.1021/ja01168a043
日期:1950.12
[1,2]- and [1,4]-Wittig rearrangements of α-alkoxysilanes: effect of substitutions at both the migrating benzylic carbon and the terminal sp2 carbon of the allyl moiety
作者:Edith N. Onyeozili、Luis M. Mori-Quiroz、Robert E. Maleczka
DOI:10.1016/j.tet.2012.10.091
日期:2013.1
Substituted alpha-alkoxysilanes can be deprotonated by alkyllithium bases and made to undergo Wittig rearrangements to afford the [1,4]- and [1,2]-rearranged products in varying ratios. Substitution at the benzylic migrating carbon and/or at the allylic carbon of the allyl moiety impacts the rearrangement reaction, influencing the reactivity as well as the [1,4]-/[1,2]-selectivity. Diastereomeric alpha-alkoxysilanes show different reactivities with the syn diastereomer being the more reactive isomer. (c) 2012 Elsevier Ltd. All rights reserved.