Tandem sequence of cross metathesis--ring-closing metathesis reaction of alkynyl silyloxy-tethered enynes.
A tandem cross metathesis (CM)--ring-closing metathesis (RCM) sequence to form cyclic siloxanes is reported. This new enyne metathesis platform expands the scope and utility of the regio- and stereoselective cross metathesis reaction between silylated alkynes and terminal alkenes. The initial cross metathesis was directed to occur on the alkyne by employing sterically hindered mono-, di-, and trisubstituted alkenes tethered to the alkyne via silyl ether. The regio- and stereoselectivity feature of the initial CM step in this tandem CM-RCM process is identical to that of the CM reactions of silylated alkynes and alkenes. This tandem sequence provides both synthetically useful silylated 1,3-diene building blocks and insights into the reaction mechanism of the enyne metathesis reaction.
Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
Sangho
S
Park
Mansuk
M
Kim
Daesung
D
Lee
D000466:Alkadienes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D003500:Cyclization; D004987:Ethers / Q000737:chemistry; D008956:Models, Chemical; D012821:Silanes / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry*
D000466:Alkadienes; D000475:Alkenes; D000480:Alkynes; D004987:Ethers; D012821:Silanes; D012833:Siloxanes