Tandem Sequence of Cross Metathesis−Ring-Closing Metathesis Reaction of Alkynyl Silyloxy-Tethered Enynes

• Published in: Journal of the American Chemical Society Vol. 127; no. 26; pp. 9410 - 9415
• Main Authors: Park, Sangho, Kim, Mansuk, Lee, Daesung
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 06.07.2005; Amer Chemical Soc
• Subjects: Alkadienes - chemistry; Alkenes - chemistry; Alkynes - chemistry; Chemical reactivity; Chemistry; Chemistry, Multidisciplinary; Cyclization; Ethers - chemistry; Exact sciences and technology; Models, Chemical; Organic chemistry; Physical Sciences; Reactivity and mechanisms; Science & Technology; Silanes - chemistry; Siloxanes - chemistry; REARRANGEMENT; ETHERS; ENANTIOSELECTIVE SYNTHESIS; HETEROCYCLES; MECHANISM; CONSTRUCTION; EFFICIENT SYNTHESIS; OLEFIN-METATHESIS; RUTHENIUM CATALYST; METAL-CARBON BONDS; Stereoselectivity; Acetylenic compound; Regioselectivity; Six membered ring; Metathesis; Experimental study; Tandem reaction; Oxygen silicon heterocycle; Heterocyclization; Ethylenic compound
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0520159

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.