Formation and reactivity of silacyclopropenes derived from siloxyalkynes: stereoselective formation of 1,2,4-triols.
Silver phosphate-catalyzed silylene transfer to siloxyalkynes provided silacyclopropenes possessing a silyl enol ether functional group. Copper-catalyzed insertions of carbonyl compounds afforded the corresponding oxasilacyclopentenes. The embedded silyl enol ether functionality was treated with various aldehydes and a catalytic amount of Sc(OTf)3 to provide dioxasilacycloheptanones, which resulted from an aldol addition/rearrangement. Stereoselective reduction or allylation of the cyclic ketone, followed by n-Bu4NF deprotection, provided high yields of 1,2,4-triols possessing four contiguous stereocenters.
Clark
Timothy B
TB
Department of Chemistry, University of California-Irvine, CA 92697-2025, USA.
Woerpel
K A
KA
D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003521:Cyclopropanes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry
D000480:Alkynes; D003521:Cyclopropanes; D017646:Organosilicon Compounds; D010710:Phosphates; D018030:Silver Compounds; C021985:cyclopropene; C039072:silver phosphate