Abstract
Lithiation of N ′-(2-methylbenzyl)-N ,N -dimethylurea
and N -(2-methylbenzyl)pivalamide with
two mole equivalents of tert -butyllithium
at -78 ˚C takes place on the nitrogen
and on the methyl group at position 2. The lithium reagents thus
obtained react with a variety of electrophiles to give the corresponding
side-chain-substituted derivatives in high yields. Dehydration of
the products obtained from reactions with carbonyl compounds in
some cases gives the corresponding tetrahydroisoquinolines in excellent
yields, while in other cases dehydration takes place within the
substituted side chain to produce the corresponding alkenes in excellent
yields.
Key words
lateral lithiation - isoquinolines -
N ′-(2-methylbenzyl)-N ,N -dimethylurea -
N -(2-methylbenzyl)pivalamide - dehydration
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