Directed lithiation of 1-acylindole derivatives was investigated. It was discovered that a bulky 2, 2-diethylbutanoyl (DEB) group could promote unusual C-7 lithiation. Especially in the case of 3-substituted 1-(DEB) indoles, selective C-7 lithiation was achieved in a synthetically useful level. The DEB group was readily removed by H2O/tert-BuOK/THF system after functionalization at C-7. This, therefore, allows easy generation of 3, 7-disubstituted indole ...
