75421-80-6Relevant articles and documents
Regioselective and oxidant-free sulfinylation of indoles and pyrroles with sulfinamides
Ji, Yuan-Zhao,Zhang, Jin-Yu,Li, Hui-Jing,Han, Chunguang,Yang, Yi-Kun,Wu, Yan-Chao
, p. 4789 - 4800 (2019/05/24)
An unexpected time-controlled highly selective C3-or C2-sulfinylation of pyrroles with sulfinamides is reported for the first time. The sulfinylation of indoles with sulfinamides using this protocol is oxidant-free and can be performed under obviously more feasible conditions (1.2 equiv. of indoles, 10 min) in comparison with the precedent procedure (3-20 equiv. of indoles, 16-18 h, ammonium persulfate as oxidant, hv). A variety of functional groups were tolerated, and various C2-thioindoles and C2/3-thiopyrroles were obtained in moderate to excellent yields.
N-(Triisopropylsilyl)pyrrole. A Progenitor "Par Excellence" of 3-Substituted Pyrroles
Bray, Brian L.,Mathies, Peter H.,Naef, Reto,Solas, Dennis R.,Tidwell, Thomas T.,et al.
, p. 6317 - 6328 (2007/10/02)
A very effective strategy has been devised for the synthesis of 3-substituted pyrroles based on the use of the triisopropylsilyl (TIPS) moiety as a sterically demanding nitrogen substituent to obstruct the attack of electrophilic reagents at the α positions. 1-(Triisopropylsilyl)pyrrole (1) undergoes highly preferential kinetic electrophilic substitution at the β position with a variety of electrophiles (Br+, I+, NO2+, RCO+, etc.) and fluoride ion induced desilylation of the products provides the corresponding 3-substituted pyrroles in good overall yields.Competitive trifluoroacetylation experiments demonstrate that substitution of TIPS-pyrrole at the α positions is decelerated by a factor of >104, vs pyrrole at the same sites, without affecting reactivity at the β positions. 1-(Triisopropylsilyl)-3-bromopyrrole (2) is readily converted into the 3-lithio compound 44 by bromine-lithium interchange with alkyllithium reagents.This previously unavailable, formal equivalent of 3-lithiopyrrole is itself an excellent source of a wide range of β-substituted pyrroles, many of which would not be directly preparable from 1.TIPS-pyrrole can be 3,4-dihalogenated and these compounds undergo sequential halogen-metal interchange trapping reactions.This process is exemplified by an efficient, three-step synthesis of the antibiotic verrucarin E (63) from the dibromo compound (5).
Synthesis and Rearrangement of 2-(Arylsulfinyl)- and 2-(Alkylsulfinyl)pyrroles
Carmona, Olga,Greenhouse, Robert,Landeros, Rosita,Muchowski, Joseph M.
, p. 5336 - 5339 (2007/10/02)
Pyrrole and N-methylpyrrole reacted with aryl- and alkylsulfinyl chlorides, at 0 deg C, to give the corresponding 2-sulfinylpyrroles as the major products only when contact of the products with the liberated hydrogen chloride was minimized or eliminated.If this precaution was not taken, the 3-sulfinylpyrroles were the principle products.In contrast, N-(phenylsulfinyl)succinimide (2a) reacted, at room temperature, with a variety of pyrroles to produce the 2-phenylsulfinyl compounds in good yields.The 2-(arylsulfinyl)- and 2-(alkylsulfinyl)pyrroles undergo a remarkably facile acid-promoted rearrangement to the isomeric 3-sulfinylpyrroles.This transposition is, at least in part, an intermolecular process as demonstrated by crossover experiments.
