Synthesis of Functionalized Vinyl Boronates via Ruthenium-Catalyzed Olefin Cross-Metathesis and Subsequent Conversion to Vinyl Halides
作者:Christie Morrill、Robert H. Grubbs
DOI:10.1021/jo0345345
日期:2003.7.1
using ruthenium-catalyzed olefin cross-metathesis of 1-propenyl pinacol boronate and various alkenes, including functionalized and 1,1-disubstituted alkenes. The resultant boronate cross products are stereoselectively transformed into predominantly Z-vinyl bromides and E-vinyl iodides. The vinyl bromides may be synthesized in a two-step, one-pot synthesis from a variety of olefins, resulting in a Z-selective
Stereochemical Inversion in the Vinylic Substitution of Boronic Esters To Give Iodonium Salts: Participation of the Internal Oxy Group
作者:Morifumi Fujita、Hee Jin Lee、Tadashi Okuyama
DOI:10.1021/ol0601850
日期:2006.3.1
[reaction: see text] Alkenylboronic esters having an acyloxy, alkoxy, or methoxycarbonyl group were employed for the reaction with (diacetoxyiodo)benzene in the presence of BF(3).OEt(2) to provide the alkenyliodonium tetrafluoroborates with inversion of configuration: (E)- and (Z)-boronates give (Z)- and (E)-iodonium salts, respectively. This selectivity can be reversed by the addition of ether to
E/Z-Selectivity Controlled by Participation of Internal Oxy Group During Electrophilic Substitution of Alk-1-enylboronate with Bis(2,4,6-trimethylpyridine)iodonium Salt
observed in electrophilic iodo-substitution of 4-benzoyloxybut-1-enylboronate using bis(2,4,6-trimethylpyridine)iodine(I) salt, rationalized by participation of the internal benzoyloxy group. Stereospecific inversion of configuration was observed in electrophilic iodo-substitution of 4-benzoyloxybut-1-enylboronate using bis(2,4,6-trimethylpyridine)iodine(I) salt, rationalized by participation of the internal