19530-43-9Relevant articles and documents
An efficient synthesis of some thiopyranopyrazole-heterocycles via domino reaction in a Bronsted acidic ionic liquid
Parmar, Narsidas J.,Parmar, Bhagyashri D.,Sutariya, Tushar R.,Kant, Rajni,Gupta, Vivek K.
, p. 6060 - 6064 (2014)
The thiopyrazole gave many new polycyclic thiopyranopyrazole-heterocycles when it was assembled with a variety of O-alkenylated/alkynylated salicylaldehydes and naphthaldehydes in Bronsted acidic ionic liquid, [Hmim]HSO4, via domino/Knoevenagel-hetero-Diels-Alder (DKHDA) reaction. The reaction is highly stereoselective and the work-up procedure required no chromatography of products in many cases.
New one-step procedure for the synthesis of 6H-chromeno[4,3-b]quinolines and 8a,9,14,14a-tetrahydro-8H-benzo[5,6]chromeno[4,3-b]quinolines
Tomashevskaya,Tomashenko,Tomashevskii,Sokolov,Potekhin
, p. 77 - 82 (2007)
Schiff bases generated in situ from substituted anilines and 2-allyloxybenzaldehyde underwent acid-catalyzed intramolecular Diels-Alder reaction followed by dehydrogenation to give 6H-chromeno[4,3-b]-quinolines. Under analogous conditions, derivatives of 2-allyloxynaphthalene-1-carbaldehyde were converted into 8a,9,14,14a-tetrahydro-8H-benzo[5,6]chromeno[4,3-b] quinolines. Possible dehydrogenation mechanisms are discussed.
Metal-free synthesis of phosphinoylchroman-4-ones via a radical phosphinoylation–cyclization cascade mediated by K2S2O8
Liu, Qiang,Lu, Weibang,Wang, Xiaoxia,Xie, Guanqun
supporting information, p. 1974 - 1982 (2020/10/02)
A variety of chroman-4-ones bearing phosphine oxide motifs were conveniently synthesized from readily available diphenylphosphine oxides and alkenyl aldehydes via a metal-free tandem phosphinoylation/cyclization protocol. The reaction utilizes K2S2O8 as oxidant and proceeds in DMSO/H2O at environmentally benign conditions with a broad substrate scope and afforded the title compounds in moderate yields.
Catalytic Intramolecular Cycloaddition Reactions by Using a Discrete Molecular Architecture
Roy, Bijan,Devaraj, Anthonisamy,Saha, Rupak,Jharimune, Suprita,Chi, Ki-Whan,Mukherjee, Partha Sarathi
, p. 15704 - 15712 (2017/10/23)
A discrete tetragonal tube-shaped complex (MT-1) has been synthesised by coordination-driven self-assembly of a carbazole-based tetraimidazole donor L and a Pd(II) 90° acceptor, that is, [cis-(dppf)Pd(OTf)2] (dppf=diphenylphosphinoferrocene, OTf=CF3SO3?). Complex MT-1 was characterised by multinuclear NMR, ESI-MS and single-crystal X-ray diffraction analysis (SCXRD), which showed its symmetrical tetrafacial tube-shaped architecture possessing a large cavity described by four aromatic walls. This coordination cage was successfully utilised as a molecular vessel to perform intramolecular cycloaddition reactions of O-allylated benzylidinebarbituric acid derivatives inside its confined nanospace. The presence of a catalytic amount of MT-1 promoted [4+2] cycloaddition reactions in a regio- and stereoselective manner, yielding the corresponding penta/tetracyclouracil derivatives in good yields under mild reaction conditions. This protocol is interesting compared with the literature reports for the synthesis of similar chromenopyran pyrimidinedione derivatives under high-temperature reflux conditions or solid-state melt reactions (SSMRs).
