Regioselective Synthesis of Benzazetines and Indoles from Alkenylanilides and Dimethyl(methylthio)sulfonium Trifluoromethanesulfonate

Abstract

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Organocatalytic Synthesis of Benzazetidines by Trapping Hemiaminals with Protecting Groups

“…[6][7][8][9] These small and strained N-heterocycles are potentially promising for applications in drug design and biomedical research. 7,10 However the synthesis of benzazetidine and their reactivity remain largely unexplored because of the scarcity of effective synthetic methodologies towards this class of compounds [6][7][8][9][11][12][13] which stems from their relative instability. 6,8,14 They also attract interest because, in the family of the fused four-membered N-heterocycles, the fused β-lactams account for the largest share of research efforts and, consequently, there is a lack of diversity among these compounds in the literature.…”

Benzazetidines and Related Compounds: Synthesis and Potential

“…The same iodoamination reaction leading to benzazetidines can be performed with N ‐iodosuccinimide in CH 2 Cl 2 , although the authors of a previous research report claim that the major product, in very similar reaction conditions, is the 3‐iodomethyl‐ N ‐acetylindoline . The nucleophilic substitution of the iodine of 2 h can be accomplished with a number of nucleophiles, for example, sodium benzenethiolate to give a 2‐(phenylthiomethyl)benzazetidine in satisfactory yields (55–66 %) …”

“…A variation of this synthetic approach was accomplished by Okuma et al . They reported a synthetic procedure using the same starting material as the synthesis in Scheme , that is, o ‐vinylbenzanilide 31 a .…”

Indole synthesis: a review and proposed classification

“…Mark Lautens of the University of Toronto established 78 that ortho dihaloalkylidene anilines, such as 171 (Scheme 65) could be condensed with alkyl, alkenyl or aryl boranes or boronic acids to give the 2-substituted indole, in this case 172 . Kentaro Okuma of Fukuoka University found 79 that the sulfonium salt 174 (Scheme 66) effected cyclization of an ortho alkenyl aniline, such as 173 to the indole 175 . Jeffrey N. Johnston, now at Vanderbilt University, effected 80 free radical reductive cyclization of halides, such as 176 (Scheme 67), to give the indole 177 .…”