Clean five-step synthesis of an array of 1,2,3,4-tetra-substituted pyrroles using polymer-supported reagents

Oxoammonium Resins as Metal-Free, Highly Reactive, Versatile Polymeric Oxidation Reagents

“…[15,16] One resin of this type has been recently employed in a reaction sequence leading to heterocyclic compounds. [17] However, low reactivity with nonbenzylic alcohols, potential persistence of highly toxic heavy metals in the products as well as overoxidation of aldehydes limits the use of solid-supported metal oxides in parallel syntheses.…”

Five‐Membered Heterocycles: Pyrrole and Related Systems

“…Alternatively, the nitroolefin components may be replaced by a,b-unsaturated sulfone derivatives [155][156][157] or by acetate precursors bearing a vicinal nitro group [158]. A variant of this reaction involving polymer supported reagents has also been developed [159]. Synthesis of the fused pyrrole derivatives 114 and 115 from 9-nitrophenanthrene (116) constitutes an interesting application of the Barton-Zard approach (Scheme 4.33) [160,161].…”

Phosphazene: Preparation, Reaction and Catalytic Role

“…Polymer-supported reagents and other solid sequestering agents can be used to generate an array of 1,2,3,4-tetrasubstituted pyrrole derivatives without any chromatographic purification step [31] (Scheme 5.14).…”