Synthesis of Highly Enantioenriched Propelladienes and their Application as Ligands in Asymmetric Rh-Catalyzed 1,4-Additions
作者:Tommaso Pecchioli、Mathias Christmann
DOI:10.1021/acs.orglett.8b02204
日期:2018.9.7
The first synthesis of highly enantioenriched [4.3.3]propelladienes is reported. The novel bridged bicyclo[3.3.0] dienes were applied as steering ligands in the rhodium-catalyzedasymmetric arylation of cyclic enones. The catalytic system showed high catalytic activity, and the 1,4-adducts were obtained in good to excellent yields (46–99%) with enantioselectivities up to 96% ee.
A series of Wieland-Miescher ketone analogues bearing highly functionalized substituents are efficiently constructed in high enantioselectivities and good yields using catalytic amounts of prolinamide and PPTS. We have successfully utilized this reaction as a key step to synthesize the tricyclic core of cylindricine type alkaloids.
<i>Illicium</i>Sesquiterpenes: Divergent Synthetic Strategy and Neurotrophic Activity Studies
作者:Lynnie Trzoss、Jing Xu、Michelle H. Lacoske、William C. Mobley、Emmanuel A. Theodorakis
DOI:10.1002/chem.201300198
日期:2013.5.10
that diverge from tetracyclic key intermediate 7. The synthesis of 7 is highlighted by the use of an enantioselective Robinson annulationreaction (construction of the AB rings), a Pd‐mediated carbomethoxylation reaction (construction of the C ring), and a one‐pot oxidative reactioncascade (construction of the D ring). Evaluation of the neurotrophic activity of these compounds led to the identification
e has been devised, which exhibits excellent activities in aminocatalyzed aldol reactions, leading to aldol products in high yields and enantioselectivities in the presence of an equimolar amount of a Bronsted acid. This organocatalyst has demonstrated remarkable reactivities in aldol processes even with equimolar amounts of aldehyde and ketone in THF. A discussion of the role of the Bronsted acid
Synthesis of the tetracyclic core of <i>Illicium</i> sesquiterpenes using an organocatalyzed asymmetric Robinson annulation
作者:Lynnie Trzoss、Jing Xu、Michelle H Lacoske、Emmanuel A Theodorakis
DOI:10.3762/bjoc.9.126
日期:——
An enantioselective synthesis of the core framework of neurotrophic Illicium majucin-type sesquiterpenes is described here. This strategy is based on an organocatalyzedasymmetric Robinson annulation and provides an efficient approach for a diversity-oriented synthesis of Illicium naturalproducts that holds remarkable therapeutic potential for neurodegenerative diseases.