Herein we describe compositions and methods for the synthesis of [2.2.2]-diazabicyclic structures comprising a domino reaction sequence involving aldol condensation, alkene isomerization, and intramolecular hetero-Diels-Alder cycloaddition. Excellent diastereofacial control during the cycloaddition is enforced with a removable chiral phenyl aminal diketopiperazine substituent. The reaction sequence rapidly generates molecular complexity and is competent with both enolizable and non-enolizable aldehyde substrates. This method provides an efficient route to [2.2.2]-diazabicyclic structures, common to bioactive prenylated indole alkaloids such as the brevianamides and stephacidins.
Efficient Entry to the [2.2.2]-Diazabicyclic Ring System via Diastereoselective Domino Reaction Sequence
作者:Kaila A. Margrey、Alex J. Chinn、Stephen W. Laws、Robert D. Pike、Jonathan R. Scheerer
DOI:10.1021/ol3007056
日期:2012.5.18
A domino reactionsequence involving aldol condensation, alkene isomerization, and intramolecular hetero-Diels–Alder cycloaddition for the synthesis of [2.2.2]-diazabicyclic structures is reported. Excellent diastereofacial control during the cycloaddition is enforced with a removable chiral phenyl aminal diketopiperazine substituent. The reactionsequence rapidly generates molecular complexity and