A convenient synthesis ofp-substituted 1-arylsulfonyl-pyrrolidin-2-ones
摘要:
A convenient and novel method of cyclisation of 4-(4-substituted-phenylsulfonamido)-butanoic acids to their corresponding p-substituted 1-arylsulfonyl-pyrrolidin-2-ones was achieved by using polyphosphate ester (PPE). The reaction times were considerably reduced, with an increase in yields, when PPE was used in combination with a catalytic amount of pyridine.
A simple and robust one-pot nucleophilic addition–ring contraction of α-bromo N-sulfonylpyrrolidinones has been achieved toward α-carbonylated N-sulfonylazetidines. In the presence of potassium carbonate, various nucleophiles, such as alcohols, phenols or anilines, have been efficiently incorporated into the azetidine derivatives. Moreover, the α-bromopyrrolidinone precursors could be selectively obtained
N-sulfonylated lactams of various ring sizes (from 5- to 8-membered rings) followed by a ring contraction reaction. The selective monohalogenation of N-sulfonyl lactams has been achieved in modest to excellent yields (9 examples, 39–96%) using N-halogenosuccinimides via the in situ generation of trimethylsilyl ketene aminal derivatives. The so-obtained α-halogeno N-sulfonyl lactams were engaged in
facilitate for the first time the intramolecular aza- and oxa-Michael reactions of α,β-unsaturated carboxylic acids. The combination of an arylboronic acid with a chiral aminothiourea allowed for these reactions to proceed successfully in an enantioselective manner to afford the desired heterocycles in high yields and ee’s (up to 96% ee). The overall utility of this dual catalytic system was demonstrated by
Synthesis of α‐Aryl Acrylamides via Lewis‐Base‐Mediated Aryl/Hydrogen Exchange
作者:Miran Lemmerer、Haoqi Zhang、Anthony J. Fernandes、Tobias Fischer、Marianne Mießkes、Yi Xiao、Nuno Maulide
DOI:10.1002/anie.202207475
日期:2022.10.4
A DABCO-induced polar aryl migration allows for the synthesis of α-aryl acrylamides from sulfonyl acrylimides. This reaction proceeds through a formal aryl/hydrogenexchange, including SO2 loss. A range of valuable building blocks have been synthesised and the underlying reaction mechanism has been explored using quantum chemical calculations.
The oxidative cleavage reaction of pyrrolidine-2-methanols to γ-lactams has been described. In this reaction, [4-iodo-3-(isopropylcarbamoyl)phenoxy]acetic acid and powdered Oxone (2KHSO5·KHSO4·K2SO4) were employed as the catalyst and co-oxidant, respectively. The reaction is efficient and environmentally benign because it produces various lactams from readily available substrates in moderate to excellent