Palladium-catalyzed asymmetric alkylation in the synthesis of cyclopentanoid and cycloheptanoid core structures bearing all-carbon quaternary stereocenters
作者:Allen Y. Hong、Nathan B. Bennett、Michael R. Krout、Thomas Jensen、Andrew M. Harned、Brian M. Stoltz
DOI:10.1016/j.tet.2011.10.031
日期:2011.12
reagents enabled divergent access to γ-quaternary acylcyclopentenes through a ringcontraction pathway or γ-quaternary cycloheptenones through a carbonyl transposition pathway. Synthetic applications of these compounds were explored through the preparation of mono-, bi-, and tricyclic derivatives that can serve as valuable intermediates for the total synthesis of complex natural products. This work complements
Ring‐Contraction Strategy for the Practical, Scalable, Catalytic Asymmetric Synthesis of Versatile γ‐Quaternary Acylcyclopentenes
作者:Allen Y. Hong、Michael R. Krout、Thomas Jensen、Nathan B. Bennett、Andrew M. Harned、Brian M. Stoltz
DOI:10.1002/anie.201007814
日期:2011.3.14
Contraction action! A simple protocol for the catalyticasymmetricsynthesis of highly functionalized γ‐quaternaryacylcyclopentenes (see schematic) in up to 91 % overall yield and 92 % ee has been developed. The reaction sequence employs a palladium‐catalyzed enantioselective alkylation reaction and exploits the unusual stability of β‐hydroxy cycloheptanones to achieve a general and robust method