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Reactivity of 5‐(Alkynyl)dibenzothiophenium Salts: Synthesis of Diynes, Vinyl Sulfones, and Phenanthrenes
Author(s) -
Kafuta Kevin,
Rugen Christian J.,
Heilmann Tobias,
Liu Tianshu,
Golz Christopher,
Alcarazo Manuel
Publication year - 2021
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202100323
Subject(s) - chemistry , sulfonium , phenanthrenes , nucleophile , reactivity (psychology) , alkyne , dibenzothiophene , organic chemistry , triple bond , medicinal chemistry , double bond , salt (chemistry) , sulfur , phenanthrene , catalysis , medicine , alternative medicine , pathology
The reactivity of 5‐(alkynyl)dibenzothiophenium salts 1 is explored in the presence of different nucleophiles, dienes, and under photochemical conditions. Reaction with lithium acetylides affords diynes in moderate yields; while depending on the substitution pattern, the reaction with sulfinates delivers either the alkyne transfer products, alkynyl sulfones, or β‐(sulfonium) vinyl sulfones through addition to the C−C triple bond. Similar behavior is observed when tosylamines are used as nucleophiles. Salts of general formula 1 also react with dienes to render the corresponding Diels‐Alder cycloadducts. The vinyl sulfonium salts obtained by these routes further react with nucleophiles through a Michael addition, dibenzothiophene elimination sequence. Alternatively, they also engage in photoinduced radical cyclizations to produce substituted phenanthrenes. Attempts to use this specific addition/radical cyclization sequence for the construction of the 6 a ,7‐dehydroaporphine skeleton present in several families of alkaloids are also described.