(2-Tetrahydrofuryl)-silanes and -germanes were obtained in high yield by the heterogeneous liquid-phase hydrogenation of [2-(4,5-dihydrofuryl)]trimethylsilane (I), bis[2-(4,5-dihydrofuryl)]dimethylsilane (II) and [2-(4,5-dihydrofuryl)]trimethylgermane with a Pd/Al2O3 catalyst. The dihydrofurylsilanes I and II were found to undergo disproportionation and dehydrogenation, the latter being involved in
通过[2-(4,5-二氢呋喃基)]三甲基硅烷(I),双[2-(4,5-二氢呋喃基)的异相液相加氢,高产率地获得了(2-四氢呋喃基)-硅烷和-锗烷。含Pd / Al 2 O 3催化剂的]二甲基硅烷(II)和[2-(4,5-二氢呋喃基)]三甲基锗烷。发现二氢呋喃基硅烷I和II经历歧化和脱氢,后者参与分子内和分子间歧化。
Palladium-catalyzed asymmetric intermolecular Mizoroki–Heck reaction for construction of a chiral quaternary carbon center
A palladium-catalyzed asymmetric intermolecular Mizoroki-Heck reaction for the construction of chiral quaternarycarboncenter is developed, affording 2,2-disubstituted 2,5-dihydrofurans in high yield with excellent enantioselectivity. The products are easily converted...
Dichlorocarbene generated in a two-phase catalytic system reacts with 3-trimethylsilyl-2,5-dihydrofuran to give both possible products of mono-insertion into the CH bond in positions 2 and 5 of the ring, together with a CC bond adduct. Reaction of 2-trimethylsilyl-4,5-dihydrofuran with dichlorocarbene leads to 2,3-dichloro-2-trimethylsilyl-5,6-dihydro-2H-pyran, which is formed via isomerization of