Diastereoselective Oxidative CN/CO and CN/CN Bond Formation Tandems Initiated by Visible Light: Synthesis of Fused<i>N</i>-Arylindolines
作者:Scott A. Morris、Theresa H. Nguyen、Nan Zheng
DOI:10.1002/adsc.201500317
日期:2015.7.6
The synthesis of fused N‐arylindolines using visiblelight photoredox catalysis has been developed. We previously described that photogenerated amine radical cations generate substituted indoles through an intermediate benzylic carbocation. Herein, we expand the application of this chemistry by trapping the benzylic carbocation with tethered heteronucleophiles. The reactivity of the photogenerated
The first totalsynthesis of the naturally occurring enantiomer of exiguolide ((−)-1) has been completed. This very convergent synthesis features the following as main steps: (i) a Trost’s ruthenium-catalyzed ene−yne cross-coupling reaction (this complex transformation allows the challenging control of the C5−C28 double bond geometry along with the stereoselective construction of the tetrahydropyran
Synthesis of the C21–C34 fragment of antascomicin B
作者:John M. Hutchison、Andrew S. Gibson、David T. Williams、Matthias C. McIntosh
DOI:10.1016/j.tetlet.2011.09.027
日期:2011.11
The C21–C34 fragment of the potent FKBP12-binding macrolide antascomicinB was prepared using Ireland-Claisen and allylic diazene rearrangements to establish the C26/C27 and the C23 stereocenters, respectively. Directed hydrogenation installed the C29 β-configuration. The fragment possesses 7 of the 11 fixed stereocenters contained in the natural product.
A Two-Component Alkyne Metathesis Catalyst System with an Improved Substrate Scope and Functional Group Tolerance: Development and Applications to Natural Product Synthesis
作者:Sebastian Schaubach、Konrad Gebauer、Felix Ungeheuer、Laura Hoffmeister、Marina K. Ilg、Conny Wirtz、Alois Fürstner
DOI:10.1002/chem.201601163
日期:2016.6.13
standard catalyst 1 largely failed to effect the critical macrocyclization, whereas the two‐component system was fully operative. A study directed toward the quinolizidine alkaloid lythrancepine I features yet another instructive example, in that a triyne substrate was metathesized with the help of 3/11 such that two of the triple bonds participated in ring closure, while the third one passed uncompromised
Aromatic Heterocycles as Activating Groups for Asymmetric Conjugate Addition Reactions. Enantioselective Copper-Catalyzed Reduction of 2-Alkenylheteroarenes
作者:Leszek Rupnicki、Aakarsh Saxena、Hon Wai Lam
DOI:10.1021/ja904365h
日期:2009.8.5
been demonstrated through development of highly enantioselective 1,4-reductions of 2-alkenylheteroarenes, substrates that have been rarely considered for asymmetric conjugate addition reactions. Both azoles and azines serve as efficient activating groups for this process.