5205-12-9Relevant articles and documents
Iron-Catalyzed Reductive Vinylation of Tertiary Alkyl Oxalates with Activated Vinyl Halides
Chen, Haifeng,Gong, Hegui,Yao, Ken,Ye, Yang
supporting information, (2020/03/13)
We present herein a rare and efficient method for the creation of vinylated all carbon quaternary centers via Fe-catalyzed cross-electrophile coupling of vinyl halides with tertiary alkyl methyl oxalates. The reaction displays excellent functional group tolerance and broad substrate scope, which allows cascade radical cyclization and vinylation to afford complex bicyclic and spiral structural motifs. The reaction proceeds via tertiary alkyl radicals, and the putative vinyl-Br/Fe complexation appears to be crucial for activating the alkene and enabling a possibly concerted radical addition/C-Fe forming process.
Weakening C-O bonds: Ti(III), a new reagent for alcohol deoxygenation and carbonyl coupling olefination
Dieguez, Horacio R.,Lopez, Armando,Domingo, Victoriano,Arteaga, Jesus F.,Dobado, Jose A.,Herrador, M. Mar,Quilez Del Moral, Jose F.,Barrero, Alejandro F.
supporting information; experimental part, p. 254 - 259 (2010/03/25)
Investigations detailed herein, including density functional theory (DFT) calculations, demonstrate that the formation of either alkoxy- or hydroxy-Ti(III) complexes considerably decreases the energy of activation for C-O bond homolysis. As a consequence of this observation, we described two new synthetic applications of Nugent's reagent in organic chemistry. The first of these applications is an one-step methodology for deoxygenation-reduction of alcohols, including benzylic and allylic alcohols and 1,2-dihydroxy compounds. Additionally, we have also proved that Ti(III) is capable of mediating carbonyl coupling-olefination. In this sense, and despite the fact that for over 35 years it has been widely accepted that either Ti(II) or Ti(0) was the active species in the reductive process of the McMurry reaction, the mechanistic evidence presented proves the involvement of Ti(III) pinacolates in the deoxygenation step of the herein described Nugent's reagent-mediated McMurry olefination. This observation sheds some light on probably one of the mechanistically more complex transformations in organic chemistry. Finally, we have also proved that both of these processes can be performed catalytically in Cp 2TiCl2 by using trimethylsilyl chloride (TMSCl) as the final oxygen trap.
New methods for the synthesis of oxy-functionalizefd 1,2,4-trioxanes and 1,2,4-trioxepanes from unsaturated hydroperoxy acetals
Ushigoe, Yoshihiro,Masuyama, Araki,Nojima, Masatomo,McCullough, Kevin J.
, p. 8753 - 8756 (2007/10/03)
Oxy-functionalized 1,2,4-trioxanes or 1,2,4-trioxepanes were produced by either autoxidation of the unsaturated hydroperoxy acetals 1, or the acid-catalyzed cyclization of epox hydroperoxides 9 which were readily prepared from 1. By the appropriate choice of cyclization procedure, the structures of the resulting cyclic peroxides could be efficiently controlled.
