Zhou X, Dong G * University of Texas at Austin, USA
[4+1] vs [4+2]: Catalytic Intramolecular Coupling between Cyclobutanones and Trisubstituted Allenes via C–C Activation.
J. Am. Chem. Soc. 2015;
137: 13715-13721
Key words
rhodium catalysis - [4+1] cyclization - enantioselective reaction
Significance
C–C activation is an attractive method to functionalize strained four-membered ring systems. Zhou and Dong demonstrate the utility of allenes as a formal vinyl carbenoid in a rhodium-catalyzed asymmetric intramolecular ring expansion of cyclobutanones.
Comment
An impressive substrate scope for this C–C activation protocol is demonstrated. Challenging cyclobutanone substrates such as those that are α-substituted also worked for this methodology, albeit with slightly diminished yields.
