Cascade Reactions of β-Amino-Substituted α,β-Unsaturated Fischer Carbene Complexes with 1,5-Dien-3-ynes as a Convenient Access to Ring-Annelated Benzene Derivatives
作者:Yao-Ting Wu、Mathias Noltemeyer、Armin de Meijere
DOI:10.1002/ejoc.200500130
日期:2005.7
achieve good chemical yields. This new cascade reaction of Fischer carbene complexes provides a direct route to trindanone analogues under milder conditions than traditional methods, and is compatible with more functionalities. Compounds 14 and 15 with steroid-like skeletons were thus prepared in 54–77 % yields (4 examples) from complex 1-iPr and the bicyclic alkyne 2. Hexacycles 17 and 18 were accessible
Rhodium-Catalyzed [2 + 2 + 2] Cycloaddition of Alkenyl Isocyanates and Alkynes
作者:Robert T. Yu、Tomislav Rovis
DOI:10.1021/ja057803c
日期:2006.3.1
rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition between alkenyl isocyanates and alkynes has been developed. Heating a mixture of an alkenyl isocyanate and a symmetrical internal alkyne in the presence of [Rh(ethylene)2Cl]2/P(4-OMe-C6H4)3 in toluene delivers substituted indolizinones and quinolizinones. Depending on the substrates, a rare fragmentation of the isocyanate unit can be involved within the cycloaddition process
Rhodium(III)‐Catalyzed Allylic C(sp
<sup>3</sup>
)–H Activation of Alkenyl Sulfonamides: Unexpected Formation of Azabicycles
作者:Alexis Archambeau、Tomislav Rovis
DOI:10.1002/anie.201504150
日期:2015.11.2
Unsaturated N‐sulfonamides undergo a RhIII‐ catalyzedallylicC(sp3)H activation followed by insertion with an exogenous internal alkyne. The reaction generates [3.3.0], [4.3.0], and [5.3.0] azabicyclic structures with excellent diastereoselectivity. Deuterium labeling experiments implicate a 1,3‐Rh shift as a key step in the mechanism.
Stereochemistry and mechanisms of thermal cycloaddition reactions of conjugated enynes. The stereospecific formation of six tetrahedral centers in a single reaction
作者:Dumitru Ionescu、James V. Silverton、L.Charles Dickinson、Bernard Miller
DOI:10.1016/0040-4039(96)00103-7
日期:1996.3
Thermal condensations of penta-1,5-dien-3-ynes with two molecules of olefinic dienophiles proceed stereospecifically with retention of the configurations of the dienophiles, and with both molecules of the dienophile in each reaction adding to the same face of the dienyne.