Organocatalytic asymmetric Mannich-type reaction of N-sulfonylimines with isocyanoacetate leading to optically active 2-imidazoline-4-carboxylates

Recent Advances in the Synthesis of Imidazolines (2009–2020)

“…In 2010, Zhang et al developed the first organocatalytic asymmetric Mannich-type cycloaddition reaction of methyl isocyanoacetate (104) with N-sulfonylimines (103) to form 2-imidazolines (105) (Scheme 30). [47] The reaction used cinchona alkaloidderived organocatalysts to generate highly diastereoselective and enantioselective 2-imidazolines. Initially, optimization experiments were carried out by reacting methyl isocyanoacetate with N-p-toluenesulfonylimine in the presence of an organic base including triethylamine (TEA), 1,4-diazabicyclo[2.…”

“…In 2010, Zhang et al . developed the first organocatalytic asymmetric Mannich‐type cycloaddition reaction of methyl isocyanoacetate ( 104 ) with N ‐sulfonylimines ( 103 ) to form 2‐imidazolines ( 105 ) (Scheme ) . The reaction used cinchona alkaloid‐derived organocatalysts to generate highly diastereoselective and enantioselective 2‐imidazolines.…”

Catalytic Enantioselective Cycloaddition with Chiral Lewis Bases

“…Likewise, the enantioselective organocatalytic reaction of isocyanoacetates with imines has rarely been developed, although it represents a convenient method for the synthesis of 2-imidazoline compounds [57]. The only example of organocatalytic Mannichtype reaction involving methyl isocyanoacetate 106 and Nsulfonylimines 107 (Scheme 27) has been disclosed by Lu, Chan et al [58]. By using catalyst 105, a variety of aromatic and heteroaromatic substituents on the imine were well tolerated and yielded trans 2-imidazolines 108 with moderate to high enantioselectivities.…”

Synthesis Route to Pyrrolones from α‐Cyano α,β‐Unsaturated Ketones and α‐Isocyano Esters by Oxidative Dearomatization of 2‐Aminofuran Intermediates

“…α‐Isocyano esters (isocyanoacetates), first reported by Ugi in 1961, are well‐known glycine templates for the synthesis of substituted α‐amino acid derivatives and for the Michael addition to polarized C–C double bonds Furthermore, α‐isocyanoacetates were successfully utilized as building blocks in [3+2]‐cycloaddition reactions with various π‐systems for the synthesis of heterocycles. The formation of various N‐heterocyclic compounds such as oxazoles, imidazoles, triazolines, isoquinolines, and pyrroles by formal [3+2] cycloaddition of isocyanoacetates with carbonyl compounds, imines, azodicarboxylates, nitroalkenes, α,β‐unsaturated ketones,[3c], maleimides, carbodiimides, alkynes, and aromatic isocyanides is well developed. Cycloaddition reactions of isocyano esters with electron‐deficient olefins [such as 3‐substituted‐2‐(4‐pyridyl)acrylonitrile] were reported by the research groups of Adamo and co‐workers for the synthesis of functionalized imine derivatives [Scheme , Equation (1)].…”