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Lithiierung in α‐Stellung zum N‐Atom von Triphenylacetamiden aus cyclischen sekundären Aminen. Umlagerung metallierter Triphenylacetamide unter 1,3‐Verschiebung der Carbamoylgruppe
Author(s) -
Wykypiel Werner,
Lohmann JeanJaques,
Seebach Dieter
Publication year - 1981
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19810640510
Subject(s) - chemistry , amide , medicinal chemistry , halide , benzene , reagent , stereochemistry , organic chemistry
Lithiation in α‐Position to the N‐Atom of Triphenylacetamides from Cyclic Secondary Amines. Rearrangements of Metalated Triphenylacetamides by 1,3‐Shift of Carbamoyl Groups The reagents 2 ‐ generally available by lithiation of the triphenylacetamides 1 ‐ react with non‐enolizable carbonyl compounds and benzyl halide (s. Tables 1 and 2 , and products 3 ). The limits of thermal stability of metalated triphenylacetamides above 0° are caused by a 1,3‐shift of the carbamoyl group into the o ‐position of one of the benzene rings (s. 2b → 4 and 8a → 10 ). The barriers to rotation around the amide bonds of four triphenylacetamides are ca. 16 kcal/mol (s. 1b–e in Table 1 ).