Selective cross coupling via oxovanadium(V)-induced oxidative desilylation of benzylic silanes
作者:Toshikazu Hirao、Takashi Fujii、Yoshiki Ohshiro
DOI:10.1016/0040-4039(94)80034-0
日期:1994.10
Benzylic silanes bearing an electron-donating group at the ortho- or para-position underwent the oxovanadium(V)-induced one-electron oxidative desilylation due to low ionization potential, which was applied to the intermolecular regioselective coupling with allylic silanes or silyl enol ether.
(thermodynamic control) should be abandoned, or at least seriously amended: kinetic factors appear to exert a primary influence on the regioselectivity of such reactions. Since the two major kinetic factors (i.e., electrophilic character of and steric hindrance at a given silicon atom) have opposite effects on the orientation of the reaction, it may happen that kinetic and thermodynamic control lead to the
Stereoselective Peterson Olefinations from Bench-Stable Reagents and<i>N</i>-Phenyl Imines
作者:Manas Das、Atul Manvar、Maïwenn Jacolot、Marco Blangetti、Roderick C. Jones、Donal F. O'Shea
DOI:10.1002/chem.201500475
日期:2015.6.8
The synthesis of bench‐stable α,α‐bis(trimethylsilyl)toluenes and tris(trimethylsilyl)methane is described and their use in stereoselective Peterson olefinations has been achieved with a wide substrate scope. Product stereoselectivity was poor with carbonyl electrophiles (E/Z ∼1:1 to 4:1) though this was significantly improved by employing the corresponding substituted N‐benzylideneaniline (up to 99:1)
Aliphatic trifluromethylselenolated compounds were accessed under visible‐lightmetalfree conditions. The key to success is the use of alkylsilanes or potassium alkyltrifluoroborates in conjunction with trifluoromethylselenosulfonate and acridinium as photocatalyst.