| Budget Amount *help |
¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2002: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2001: ¥2,400,000 (Direct Cost: ¥2,400,000)
|
|---|
| Research Abstract |
We have developed new methods for preparing functionalized benzynes through deprotonative zincation as a key reaction using R_2Zn(TMP)Li, and we also describes dramatic ligand effects on the benzyne formation. Deprotonative zincation of various m-substituted bromobenzenes using Me_2Zn(TMP)Li proved effective for the one-pot generation of various 3-functionalized benzynes, particulary those with electrophilic substituents such as ester, amide, and cyano. On the other hand, zincation with ^tBu_2Zn(TMP)Li/ followed by electrophilic trapping (with I_2) proved a powerful tool for the preparation of 1,2,3-trisubstituted aromatic compounds. The resultant 1,2,3-trisubstituted benzenes are available as precursors for generation of 3-substituted benzynes by halogen-zinc exchange reactions using Me_3ZnLi. These methods offer far greater generality than previous methods for the synthesis of functionalized asymmetric benzynes, and should be value in new syntheses of various natural products and functional materials. In addition, these results underline the utility of spectator ligands on the central metal of ate complexes as a tunable functionality in the development of new ate complex-promoted reactions.
|
