通过重氮前体的光解在甲醇中生成具有不饱和邻位取代基(乙烯基氧基、1-丙烯氧基、烯丙基、2-丁烯基、2,4-戊二烯基)的芳基卡宾。发现分子间 OH 插入与双键的分子内加成竞争。与类似的分子间反应相比,三线态敏化强烈影响产物分布。根据 k S /k ST 和 k T /k TS 速率比对分子内过程的单线态和三线态成分进行剖析和评估。单线态芳基卡宾的分子内环加成反应效率很低,可能是由于需要围绕外环 C-CH: 键旋转。相比之下,相对于分子间类似物,三重芳基卡宾的非集中分子内加成强烈加速。最有可能的,
bicyclic core structures with up to three stereocenters within a single step. Herein, this concept is combined with the chemistry of chiral Brønsted acid bound ortho-quinonemethideimines to generate a range of interesting fused tetrahydroquinolines in a diastereo- and enantioselective manner.
Enantio‐ and Diastereoselective, Lewis Base Catalyzed, Cascade Sulfenoacetalization of Alkenyl Aldehydes
作者:Anastassia Matviitsuk、Scott E. Denmark
DOI:10.1002/anie.201906535
日期:2019.9.2
catalytic, enantio-, and diastereoselective formation of sulfenyl acetals bearingmultiplestereogeniccenters is reported. Alkenyl aldehydes undergo a chiral thiiranium ion initiated cascade starting with intramolecular capture by a formyl group and termination by capture with HFIP solvent. This method provides a one-potsynthesis of dihydropyran and 1,3-disubstituted isochroman acetals in good to excellent
PADWA A.; KU H., J. ORG. CHEM., 1980, 45, NO 19, 3756-3766
作者:PADWA A.、 KU H.
DOI:——
日期:——
Intramolecular addition reactions of functionalized arylcarbenes to double bonds
作者:Wolfgang Kirmse、Guenter Hoemberger
DOI:10.1021/ja00010a038
日期:1991.5
was found to compete with intramolecular addition to the doublebonds. The product distributions are strongly affected by triplet sensitization, in contrast to those of analogous intermolecular reactions. The singlet and triplet components of the intramolecular processes were dissected and evaluated in terms of k S /k ST and k T /k TS rate ratios. Intramolecularcycloaddition reactions of singlet arylcarbenes
通过重氮前体的光解在甲醇中生成具有不饱和邻位取代基(乙烯基氧基、1-丙烯氧基、烯丙基、2-丁烯基、2,4-戊二烯基)的芳基卡宾。发现分子间 OH 插入与双键的分子内加成竞争。与类似的分子间反应相比,三线态敏化强烈影响产物分布。根据 k S /k ST 和 k T /k TS 速率比对分子内过程的单线态和三线态成分进行剖析和评估。单线态芳基卡宾的分子内环加成反应效率很低,可能是由于需要围绕外环 C-CH: 键旋转。相比之下,相对于分子间类似物,三重芳基卡宾的非集中分子内加成强烈加速。最有可能的,
Intramolecular cycloaddition reactions of olefinic tosylhydrazones