Brønsted Acid-Catalyzed, Highly Enantioselective Addition of Enamides to In Situ<i>-</i>Generated<i>ortho</i>-Quinone Methides: A Domino Approach to Complex Acetamidotetrahydroxanthenes
作者:Satyajit Saha、Christoph Schneider
DOI:10.1002/chem.201406044
日期:2015.2.2
The highly enantioselective conjugate addition of enamides and enecarbamates to in situ‐generated ortho‐quinone methides, upon subsequent N,O‐acetalization, gives rise to acetamido‐substituted tetrahydroxanthenes with generally excellent enantio‐ and diastereoselectivities. A chiral BINOL‐based phosphoric acid catalyst controls the enantioselectivity of the carbon–carbon bond‐forming event. The products
A Facile and Practical Synthesis of <i>N</i>-Acetyl Enamides
作者:Wenjun Tang、Andrew Capacci、Max Sarvestani、Xudong Wei、Nathan K. Yee、Chris H. Senanayake
DOI:10.1021/jo902259u
日期:2009.12.18
A facile and practical method for the synthesis of N-acetyl α-arylenamides has been developed from corresponding ketoximes as the starting materials with ferrous acetate as the reducing reagent. This methodology offers mild reaction conditions, simple purification procedures, and high yields for a variety of N-acetyl enamides.
Visible-light-induced, UiO-67-Ru-catalyzed oxidative cross-coupling for constructing β-acetylamino acrylosulfones
作者:Siyan Xu、Hao Kong、Ronghua Zhang
DOI:10.1016/j.tetlet.2020.151629
日期:2020.3
novel approach to generate β-acetylamino acrylosulfones using the photocatalyst UiO-67-Ru under visiblelight has been developed. The entire reaction is applicable to sulfone-containing skeleton and exhibits good substrate scope. UiO-67-Ru-catalyzed protocol provides a sustainable and efficient access to construct a variety of sulfonesvia the direct functionalization of C–H bonds.
This work reports a simple and efficient method for the direct phosphorylation of enamide under metal-free conditions. The P-centered radicals, derivedfrom secondary phosphine oxides, are generated under mild reaction conditions in the presence of diphenyliodonium salt and Et3N and are introduced onto a range of enamides in good isolated yields. The method features broad substrate scope, good functional
reducing alkenes bearing metal-coordinating groups. In the present system, selectivity was pressure-dependent: In most cases, a decrease in the H2 pressure to 3 bar resulted in an increase in enantioselectivity. Moreover, the process can be carried out in environmentally friendly solvents, such as methanol and ethyl acetate, with no loss of selectivity.
MaxPHOX-Ir 催化剂系统为 α-和 β-四氢萘酮衍生的环状烯酰胺的还原提供了迄今为止报道的最高选择性。该结果表明铱催化剂也能有效还原带有金属配位基团的烯烃。在本系统中,选择性取决于压力:在大多数情况下,氢气压力降低至 3 bar 会导致对映选择性增加。此外,该过程可以在甲醇和乙酸乙酯等环保溶剂中进行,而不会损失选择性。