已经研究了氧取代的萘与单线态氧(1 O 2)的反应,并且首次分离了不稳定的过氧化物,并在–78°C下进行了表征。紫外光谱的低温动力学表明,与1,4-二甲基萘相比,烷氧基和甲硅烷氧基取代基显着提高了光氧合速率,而酰氧基取代的并苯对1 O 2呈惰性。反应性与我们通过密度泛函理论计算确定的HOMO能量和自由活化能很好地相关。分离出的过氧化物的不稳定性是由于它们即使在–20°C下在释放1时也会与相应的萘发生非常快速的逆反应。O 2,使其在非常温和的条件下成为该反应物种的上等来源。最终,合成了碳水化合物取代的萘,该萘可与1 O 2可逆反应,并可能在未来的工作中用于对映选择性氧化。
已经研究了氧取代的萘与单线态氧(1 O 2)的反应,并且首次分离了不稳定的过氧化物,并在–78°C下进行了表征。紫外光谱的低温动力学表明,与1,4-二甲基萘相比,烷氧基和甲硅烷氧基取代基显着提高了光氧合速率,而酰氧基取代的并苯对1 O 2呈惰性。反应性与我们通过密度泛函理论计算确定的HOMO能量和自由活化能很好地相关。分离出的过氧化物的不稳定性是由于它们即使在–20°C下在释放1时也会与相应的萘发生非常快速的逆反应。O 2,使其在非常温和的条件下成为该反应物种的上等来源。最终,合成了碳水化合物取代的萘,该萘可与1 O 2可逆反应,并可能在未来的工作中用于对映选择性氧化。
In the presence of a catalytic amount of iodine, hexamethyldisilane can reductively silylate p-quinones under mild conditions to afford 1,4-bis(trimethylsiloxy)arenes in high yields.
Synthesen mit verbindungen R3MHgMR3 und (R2MHg)n (MC, Si, Ge, Sn)
作者:Guido Neumann、Wilhelm P. Neumann
DOI:10.1016/s0022-328x(00)90077-9
日期:1972.9
Aromatic aldehydes are reductively dimerised by Me3SiHgSiMe3 (I), yielding bis(O-silyl)hydrobenzoin derivatives. 1,2-Diketones undergo 1,4-addition with formation of bis(O-silyl)enediols, while esters of conjugated dicarboxylic acids give O-silyl ketene acetals: maleic yields mainly the C,O-bissilyl derivative (1,4-addition), whereas fumaric and ethylene tetracarboxylic esters yield mainly the corresponding
Highly Efficient and Chemoselective Reductive Bis-silylation of Quinones by Silyltellurides
作者:Shigeru Yamago、Hiroshi Miyazoe、Kazunori Iida、Jun-ichi Yoshida
DOI:10.1021/ol006581e
日期:2000.11.1
[GRAPHICS]Silyltellurides serve as new silicon-based chemoselective reducing agents and reduce quinones to the corresponding bis-silylated hydroquinones. The reaction proceeds under ambient thermal conditions without the need of any additional promoters or catalysts and gives the products in excellent yields. Several control experiments suggest that the reaction is initiated by a single electron transfer from silyltellurides to quinones.