We report an unprecedented domino polycyclization from readily available 2,4‐dienals and cyclic α,β‐unsaturated imines that is initiated by an iso‐Nazarov reaction. This Brønsted acid promoted reaction enables the concomitant formation of four bonds, three cycles, and four contiguous stereogenic centers to yield elaborated structures in a single operation. A range of fused hexacyclic molecules is obtained
Catalytic enantioselective cascade Michael/cyclization reaction of 3-isothiocyanato oxindoles with exocyclic α,β-unsaturated ketones en route to 3,2′-pyrrolidinyl bispirooxindoles
作者:Satavisha Kayal、Santanu Mukherjee
DOI:10.1039/c6ob02187e
日期:——
Cascade Michael/cyclization reactions between 3-isothiocyanato oxindoles and exocyclic α,β-unsaturated ketones are shown to proceed efficiently in the presence of a quinine-derived tertiary amino-squaramide catalyst and furnish 3,2′-pyrrolidinyl bispirooxindoles containing two spiro-quaternary and three contiguous stereocenters as a single diastereomer with excellent enantioselectivities (up to 99 : 1
Domino reactions in water for the stereoselective synthesis of novel spiro dihydro-2′H-[indene-2,3′-thiophen]-1(3H)-ones with three contiguous stereocenters
triethylamine in water stereoselectively afforded a library of 2′-(aryl)-4′-hydroxy-4′,5′-dihydro-2′H-spiro[indene-2,3′-thiophen]-1(3H)-ones. This transformation presumably proceeds via the generation of 2-mercaptoacetaldehyde from 1,4-dithiane-2,5-diol followed by Michael addition–intramolecular aldol sequence with C–C and C–S bond formations and creation of threecontiguousstereocenters in a one-pot operation
One-pot inter- and intramolecular Friedel–Crafts reactions in Baylis–Hillman chemistry: a novel facile synthesis of ( E )-2-arylideneindan-1-ones
作者:Deevi Basavaiah、Ravi Mallikarjuna Reddy
DOI:10.1016/s0040-4039(01)00354-9
日期:2001.4
A simple one-pot stereoselective transformation of tert-butyl 3-aryl-3-hydroxy-2-methylenepropanoates, the Baylis–Hillman adducts obtained from t-butyl acrylate, into (E)-2-arylideneindan-1-ones involving one inter- and one intramolecular Friedel–Crafts reaction is described.