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Angle compression

In several cases, cyclopropylcarbinyl-homoallyl rearrangements involving zirconium species were observed (Scheme 16), similar to those reported for some other transition metals [23]. Examples of reactions are depicted in Table 3. The lack of rearrangement for the homoallylic ethers in entries 3-5 was attributed to the Thorpe-Ingold effect, i.e., angle compression at the substituted carbon [24]. [Pg.117]

Figure 12 Constrained geometry catalyst precursor featuring Cp-metal-amido bond angle compression... Figure 12 Constrained geometry catalyst precursor featuring Cp-metal-amido bond angle compression...
Transition state strain 120 — 60 = 60° angle compression /. higher activation energy... [Pg.115]

The simplest way to think about the pK, of boronic acids is to consider a solvent water molecule associated with the sp boronic acid, at high pH the water is deproto-nated and forms a tetrahedral sp boronate. On saccharide binding and formation of a cyclic boronate ester the pJC of the boronic acid is lowered, or in other words the ester is more acidic than the acid . The enhanced acidity is due to a bond angle compression on formation of a cyclic boronate ester. Boronic acids have a 120 (sp ) bond angle but on the formation of a cyclic ester the bond angle is reduced to 108 . Obvi-... [Pg.443]


See other pages where Angle compression is mentioned: [Pg.48]    [Pg.1261]    [Pg.43]    [Pg.48]    [Pg.48]    [Pg.317]    [Pg.110]    [Pg.425]    [Pg.882]    [Pg.3]    [Pg.82]    [Pg.721]    [Pg.48]    [Pg.121]    [Pg.141]    [Pg.43]    [Pg.64]    [Pg.382]    [Pg.334]    [Pg.5]    [Pg.38]    [Pg.121]    [Pg.118]    [Pg.298]    [Pg.326]    [Pg.326]    [Pg.64]    [Pg.115]    [Pg.115]    [Pg.244]    [Pg.346]    [Pg.574]    [Pg.281]    [Pg.333]    [Pg.192]    [Pg.109]    [Pg.104]    [Pg.105]    [Pg.417]    [Pg.873]    [Pg.113]    [Pg.255]    [Pg.129]    [Pg.41]    [Pg.35]    [Pg.15]   
See also in sourсe #XX -- [ Pg.317 ]




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