Remarkable tris(trimethylsilyl)silyl group for diastereoselective [2 + 2] cyclizations.
[reaction: see text] Diastereoselective [2 + 2] cyclizations of aldehyde- and ketone-derived silyl enol ethers with acrylates is described. The use of the tris(trimethylsilyl)silyl group allows for unprecedented reactivity, yields, and selectivity for these cyclizations. The presence of silicon-silicon bonds proved to be important for this transformation, where typical silyl groups (TBS and TIPS) failed to give any desired product. The bulky bis(2,6-diphenylphenoxide) aluminum triflimide catalyst was essential for high diastereoselectivity.
Department of Chemistry, University of Chicago, Illinois 60637, USA.
Matthew B
MB
Boxer
Hisashi
H
Yamamoto