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Silicon-Oxygen Heterocycles from Thermal, Photochemical, and Transition-Metal-Catalyzed Decomposition of α-(Alkoxysilyl and Alkenyloxysilyl)-α-diazoacetates

✍ Scribed by Gerhard Maas; Fred Krebs; Thorsten Werle; Volker Gettwert; Ruth Striegler


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
317 KB
Volume
1999
Category
Article
ISSN
1434-193X

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✦ Synopsis


Photolysis of (ethoxy)silyl-, (propyloxy)silyl-, and (isopro-oxasiloles 4b-d, which are likely to be formed on a pyrazoline rather than a carbene route. For (3-butenyloxysilyl)diazo-pyloxy)silyl-substituted diazoacetates 1a-c leads to tetrahydro-1,2-oxasiloles 2a-c by intramolecular C-H acetate 3f, all modes of decomposition generate the 3-oxa-2silabicyclo[4.1.0]heptane system 7.

Fluoride-induced insertion of a carbene intermediate. Photochemical or catalytic decomposition of (allyloxysilyl)diazoacetates 3a-e cleavage of the bicyclic systems 5b-d provides trans-2hydroxyalkyl-1-cyclopropanecarboxylates 9 diastereospeci-results in intramolecular cyclopropanation which provides 3oxa-2-silabicyclo[3.1.0]hexane systems 5a-e. In contrast, the fically. thermal reaction of 3b-d gives rise to 2,5-dihydro-1,2ane, resulted in a clean 1,4-CϪH insertion to form a 1,2-si-Decomposition of (Alkoxysilyl)diazoacetates 1a؊c