88312-99-6Relevant academic research and scientific papers
Carbonylation of doubly lithiated N′-aryl-N,N-dimethylureas: A novel approach to isatins via intramolecular trapping of acyllithiums
Smith, Keith,El-Hiti, Gamal A.,Hawes, Anthony C.
, p. 2047 - 2052 (2007/10/03)
Lithiation of N′-(2-bromoaryl)-N,N-dimethylureas with methyllithium and tert-butyllithium under nitrogen in anhydrous THF at 0°C gave doubly lithiated arylurea derivatives, which react with carbon monoxide at 0°C to give isatins in good yields. The scope of the reaction has been demonstrated by application to the synthesis of isatin itself and four substituted isatins beating alkyl, chloro or fluoro groups.
HETEROCYCLIC SYNTHESES VIA CARBANIONICALLY INDUCED REARRANGEMENT REACTIONS
Hellwinkel, Dieter,Lenz, Ruediger,Lammerzahl, Frank
, p. 2073 - 2084 (2007/10/02)
The easily occuring -migrations of sulfonyl and carbonyl functions to neighboring phenyl anions can be utilized for ring expansions by one benzo unit when suitably tailored precursor heterocycles are used.Thus, the 1,2- benzisothiazol dioxide systems 8 and 17 can be transformed into dibenzothiazepin dioxides 12 and 21, respectively, whereas the dibenzo- and 1,2,4-benzothiazin dioxide models 35 and 46 give rise to the tribenzothiazocin dioxide and dibenzothiadiazocin dioxide systems 38 and 47, respectively.Unexpected formations of heterocyclic systems, namely, spirobenzoxazin-5,1'(3H)-isobenzofuran> 55, 3,1-benzoxazin 62, and phenanthridinium-salt 70 took place when phtalimide 52, dibenzoylaniline 56, and biphenylylbenzamide 65 were reacted with t-BuLi.
