Intramolecular Copper- and Rhodium-Mediated Carbenoid Reactions of α-(Propargyloxy)silyl-α-diazoacetates

✍ Scribed by Volker Gettwert; Fred Krebs; Gerhard Maas

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 356 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199905)1999:5<1213::aid-ejoc1213>3.0.co;2-u

✦ Synopsis

Copper(I) triflate catalyzes the transformation of α-[(2experimental observations are explained in terms of metalmediated intramolecular cyclopropenation and subsequent alkynyl)oxy]silyl-α-diazoacetates 1a-g into 1,2-bis(2,5dihydro-1,2-oxasilol-4-yl)ethenes 2 and/or 2H-1,2-oxasilines metal-assisted ring-opening of the strained bicyclic cyclopropene leading to vinylcarbene-metal complexes. An 3. With rhodium(II) perfluorobutyrate as catalyst, 1a-e furnish only 3 but no 2. Bicyclic 2-methoxyfurans 6 are unusual autoxidation of 2H-1,2-oxasilines 3a,c,e is also described. formed when 1a,c,e (containing terminal alkyne functions) are treated with catalytic amounts of copper(I) chloride. The