Germylene Reactions with Quinones Shed Light on Germylene Phenone Equilibria
摘要:
Ge[CH(SiMe3)(2)](2) (1) and Ge[N(SiMe3)(2)](2) (2) react with anthraquinone and naphthoquinone in a 2:1 ratio to form five-membered rings with the carbonyl oxygens and the ortho carbons of the adjacent aromatic ring. The reaction with 1,4-diacetylbenzene proceeds in a similar fashion with 1; however no reaction is observed with 2. Compounds 1 and 2 react with 1,2-diacetylbenzene to yield a novel bicyclo species. In a previous report describing equilibria between 1 and phenones, it appeared that 2 did not undergo reaction to generate the five-membered ring with the accompanying formation of a conjugated triene. However, these quinone results indicate that an equilibrium can exist between 2 and a phenone moiety. In the reaction with quinones, a second equivalent of germylene effectively traps the conjugated triene by undergoing a 1,4-addition reaction. Unlike the initial triene formation, this second insertion is irreversible.
Germylene Reactions with Quinones Shed Light on Germylene Phenone Equilibria
作者:Ryan D. Sweeder、Robyn L. Gdula、Bonnie J. Ludwig、Mark M. Banaszak Holl、Jeff W. Kampf
DOI:10.1021/om0302589
日期:2003.8.1
Ge[CH(SiMe3)(2)](2) (1) and Ge[N(SiMe3)(2)](2) (2) react with anthraquinone and naphthoquinone in a 2:1 ratio to form five-membered rings with the carbonyl oxygens and the ortho carbons of the adjacent aromatic ring. The reaction with 1,4-diacetylbenzene proceeds in a similar fashion with 1; however no reaction is observed with 2. Compounds 1 and 2 react with 1,2-diacetylbenzene to yield a novel bicyclo species. In a previous report describing equilibria between 1 and phenones, it appeared that 2 did not undergo reaction to generate the five-membered ring with the accompanying formation of a conjugated triene. However, these quinone results indicate that an equilibrium can exist between 2 and a phenone moiety. In the reaction with quinones, a second equivalent of germylene effectively traps the conjugated triene by undergoing a 1,4-addition reaction. Unlike the initial triene formation, this second insertion is irreversible.