Amino-Claisen Rearrangement. II. Quaternary Amino-Claisen Rearrangement of Anilinium Compounds with ortho Substituents

抄録

Amino (N)-Claisen rearrangement of quaternary aniline derivatives with ortho substituents was investigated in relation to that of corresponding tertiary anilines. N-Allylated anilinium compounds 1 with a freely rotating ortho substituent such as a methyl or methoxy group yielded mostly the deallylated products 4 along with minor amounts of rearrangement products 2 and 3. The corresponding tertiary anilines yielded ortho rearrangement products 6 together with para ones 7. The quaternary N-Claisen rearangement of N-allylated 1, 2, 3, 4-tetrahydroquinolinium salts 14 and indolinium salts 22 in which the ortho substituents are locked in rings afforded the ortho rearrangement products 15 and 23, respectively in good yields. N-Claisen rearrangement of the corresponding aromatic tertiary amines 18 also took place in good yield. The above rearrangements could be rationalized on the basis of mechanistic considerations.