117299-06-6Relevant articles and documents
Titanium-Promoted Cross-Coupling for the Selective Synthesis of Polysubstituted, Conjugated Amides
Chenniappan, Vinoth Kumar,Rahaim, Ronald J.
, p. 5090 - 5093 (2016/10/14)
α,β-Unsaturated amides are important building blocks and are key structural elements in a number of biologically active natural products. Despite their importance and prevalence, few methods exist to prepare conjugated amides directly and modularly. To address this gap, a titanium-promoted coupling of alkynes and isocyanates has been developed. The method is highly stereoselective, producing only the E isomer with good chemoselectivity and regioselectivity (>95/5), for unsymmetrical internal alkynes that contain a steric bias. The reactive titanacyclopentene intermediate formed from the coupling of the alkyne and isocyanate was additionally reacted with various electrophiles to access tetrasubstituted enamides.
Facile synthesis of the fused 6-6-5 ring system containing chroman ring from 2-(1-hydroxy-5-alkenyl)phenol derivatives via intramolecular inverse- electron-demand diels-alder reaction
Shrestha, Kedar Shanker,Honda, Kiyoshi,Asami, Masatoshi,Inoue, Seiichi
, p. 73 - 83 (2007/10/03)
A simple and facile synthesis of the fused 6-6-5 ring system, i.e., 1,2,3,3a,4,9b-hexahydrocyclopenta[c][1]benzopyrans, was achieved through the intramolecular [4+2] cycloaddition of o-quinonemethides generated from 2-(1- hydroxy-5-alkenyl)phenol derivatives under acidic conditions. In general, cis-fused tricyclic compounds of 6-6-5 ring system were obtained as the major products. Reactivity and selectivity of the cycloaddition reaction depended on the substituents on the aromatic ring and in the dienophilic olefin moiety.
