ISSN:
0009-2940
Keywords:
1,3-Dienes, β1- and δ1-addition to electron-deficient
;
Carbene analogues
;
Germanes, allyl-
;
Germylenes
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A new type of reaction between dimethylgermylene (Me2Ge) (1), generated in situ from a 7-germanobornadiene, and electron-deficient 1,3-dienes RR′C=CH - CH=CH - Z [Z=C(O)Me, CO2R″ 2a - f] or cyclic dienones 8, 9 in the presence of water is described. The Michael-type behaviour of the system Me2Ge/H2O is clearly shown by the nucleophilic addition to the unsaturated systems resulting in the formation of β1- and δ1-adducts, the new allylgermanes 3a - g, 4a -c, 10a, b, 11. The cis configuration of the resulting double bond of the δ adducts 4a-c is remarkable. With open-chain dienes cycloaddition of 1 without participation of water, yielding germacyclopentenes 5a, b or germacyclopentanes 7a, b, competes with the Michael-type reaction. A slight variation of the substitution pattern of the dienes has a strong influence on the reaction course.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19931260330
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