1290052-39-9Relevant academic research and scientific papers
Palladium-catalyzed asymmetric alkylation in the synthesis of cyclopentanoid and cycloheptanoid core structures bearing all-carbon quaternary stereocenters
Hong, Allen Y.,Bennett, Nathan B.,Krout, Michael R.,Jensen, Thomas,Harned, Andrew M.,Stoltz, Brian M.
, p. 10234 - 10248 (2012/01/03)
General catalytic asymmetric routes toward cyclopentanoid and cycloheptanoid core structures embedded in numerous natural products have been developed. The central stereoselective transformation in our divergent strategies is the enantioselective decarboxylative alkylation of seven-membered β-ketoesters to form α-quaternary vinylogous esters. Recognition of the unusual reactivity of β-hydroxyketones resulting from the addition of hydride or organometallic reagents enabled divergent access to γ-quaternary acylcyclopentenes through a ring contraction 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 our previous work with cyclohexanoid systems.
Ring-contraction strategy for the practical, scalable, catalytic asymmetric synthesis of versatile γ-quaternary acylcyclopentenes
Hong, Allen Y.,Krout, Michael R.,Jensen, Thomas,Bennett, Nathan B.,Harned, Andrew M.,Stoltz, Brian M.
supporting information; experimental part, p. 2756 - 2760 (2011/05/05)
Contraction action! A simple protocol for the catalytic asymmetric synthesis of highly functionalized γ-quaternary acylcyclopentenes (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 for performing two-carbon ring contractions. Copyright
