intermolecular assembly of 2,2-disubstituted indolines has been developed. This protocol is based on a ligand and directing group free, iron-catalyzed radical [3 + 2] process, allowing efficient coupling of different N-sulfonylanilines with various α-substituted styrenes. Preliminary mechanistic studies elucidated the radical mechanism involving a reactive and versatile anilino radical and the importance
Preparation of acid-labile resins with halide linkers and their utility in solid phase organic synthesis
作者:Khehyong Ngu、Dinesh V. Patel
DOI:10.1016/s0040-4039(96)02502-6
日期:1997.2
preparation of acid-labile resins with displaceable halide linkers (3 and 4, X = BrandI) is described. These resins can be used in combinatorial organic synthesis of numerous drug-scaffold libraries. Their synthetic utility is exemplified by high yielding N-alkylations with structurally and electronically diverse sets of aliphatic and aromatic amines. Amongst the various resins modified and evaluated in
arylalkylation of activated alkenes via hydrogen-atomtransfer and aryl migration strategy. The reaction was carried out through a radical-mediated continuous migration pathway using N-fluorosulfonamides as the alkyl source. The primary, secondary, and tertiary alkyl radicals formed by intramolecular hydrogen-atomtransfer proceeded smoothly. This methodology is an efficient approach for the synthesis of various
A mild and efficient electrochemical method for radical addition, cyclization, and migration reaction was described in this work. A difluoromethyl radical was produced by anodizing CF2HSO2Na. The resulting product was then added to olefin, underwent Smiles cyclization, and migrated to form β-difluoromethamide compounds after the release of SO2. The process was free from metals and catalysts, gram-grade
The title compound afforded four different types of crystals as pseudopolymorphs upon crystallization from a variety of different solvents. Single-crystal X-ray analysis revealed that the nonsolvated crystals exclusively formed a zigzag chain motif through hydrogen-bonding interactions (H-bonds). In contrast, the solvent-containing crystals formed a helical chain motif through H-bonds to give rise to channel-shaped network structures. The inner spaces of the channels were occupied by solvent molecules from the crystallization solvent. These solvent-containing crystals could be converted to the nonsolvated crystals by removal of the solvent molecules by drying under reduced pressure at 45 degrees C. They also showed mutual polymorphic transitions via a solvent-exchange process.