Products of reaction between styrene and some radicals with 2,2-diphenyl-1-picrylhydrazyl

1981 ◽  
Vol 59 (21) ◽  
pp. 3095-3104 ◽  
Author(s):  
Karl R. Kopecky ◽  
Michael C. Hall
Keyword(s):  
Nitro Group ◽  
Considerable Increase ◽  
Phenyl Group ◽  
Diels Alder ◽  
Benzyl Radicals ◽  
Products Of Reaction ◽  
Cis And Trans

Addition of 2,2-diphenyl-1-picrylhydrazyl DPPH to styrene at 75 °C results in little change in the amounts of cis- and trans-1,2-diphenylcyclobutane and 1,2,3,4-tetrahydro-1-phenylnaphthalene, in a slightly smaller amount of 1-phenylnaphthalene, and in a considerable increase in the amount of 1,2-dihydro-1-phenylnaphthalene that are formed. Formation of the styrene trimer 1,2,3,4-tetrahydro-1-phenyl-4-(1-phenylethyl)naphthalene is eliminated completely. Products derived from DPPH are l-(4-nitro-phenyl)-1-phenyl-2-picrylhydrazine 9 and 1-[2,6-dinitro-4-(1,2,3,4-tetrahydro-4-phenyl-1-naphthyl)phenyl]-2,2-diphenylhydrazine, 10. DPPH intercepts the thermally formed Diels–Alder dimer of styrene as soon as it is formed to give the 1,2,3,4-tetrahydro-4-phenyl-1-naphthyl radical.Thermolysis of bis(1,2,3,4-tetrahydro-4-phenyl-1-naphthyl)diazene in the presence of DPPH yields 20% of 10, 10,% of l-[2,6-dinitro-4-(1,2,3,4-tetrahydro-4-phenyl-1-naphthyl)phenyl]-2-(4-nitrophenyl)-2-phenylhydrazine and 9 while thermolysis of 1,2-bis(1-phenylethyl)diazene in the presence of DPPH yields 9 and 44% of 1-[2,6-dinitro-4-(1-phenylethyl)phenyl]-2,2-diphenyl-hydrazine showing that substituted benzyl radicals efficiently displace the 4-nitro group of DPPH. The nitro group is transferred to an unsubstituted phenyl group of DPPH.

High Pressure Diels-Alder Reaction of 1-Methyl-2(1H)-pyridones Having a Phenyl Group with N-Phenylmaleimide

Heterocycles ◽  
1990 ◽  
Vol 30 (1) ◽  
pp. 359 ◽  
Author(s):  
Hiroshi Tomisawa ◽  
Hiroto Nakano ◽  
Hiroshi Hongo
Keyword(s):  
High Pressure ◽  
Phenyl Group ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

Photochemistry of 2,4-Cyclooctadienone I. In Benzene and Toluene

1973 ◽  
Vol 51 (13) ◽  
pp. 2207-2214 ◽  
Author(s):  
Gordon L. Lange ◽  
Eli Neidert
Keyword(s):  
Singlet State ◽  
Alder Reaction ◽  
Diels Alder ◽  
Reactive Intermediate ◽  
Diels Alder Reaction ◽  
Trans Isomerization ◽  
Dimerization Reaction ◽  
Cis And Trans

Irradiation of 2,4-cyclooctadienone (1) in benzene or toluene is shown to give in >80% yield two head-to-head dimers. The ring fusions are shown to occur at the α,β-positions of the dienone with trans-cis and trans-anti-trans stereochemistry. Both dimers may be epimerized to the same product with cis-anti-cis ring fusions. Evidence is presented to show that the singlet state is responsible for the cis-trans isomerization of 1 to the highly reactive intermediate trans, cis-2,4-cyclooctadienone. This intermediate can dimerize in a thermal 2 + 2 cycloaddition or can be generated at −78° and then trapped by 1,3-dienes in a Diels–Alder reaction. A mechanism for the dimerization reaction is discussed.

scholarly journals Recent Progress in Nitro-Promoted Direct Functionalization of Pyridones and Quinolones

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 673 ◽  
Author(s):  
Feiyue Hao ◽  
Nagatoshi Nishiwaki
Keyword(s):  
Nitro Group ◽  
Functional Groups ◽  
Recent Progress ◽  
Alder Reaction ◽  
Diels Alder ◽  
Organic Syntheses ◽  
Diels Alder Reaction ◽  
Direct Functionalization ◽  
Nucleophilic Reagents

Nitro group is one of the most important functional groups in organic syntheses because its strongly electron-withdrawing ability activates the scaffold, facilitating the reaction with nucleophilic reagents or the Diels–Alder reaction. In this review, recent progress in the nitro-promoted direct functionalization of pyridones and quinolones is highlighted to complement previous reviews.

Diels-Alder reactions of cycloalkenones. 15. Synthesis of cis- and trans-.DELTA.6-4a-methyl-1-octalones

1989 ◽  
Vol 54 (5) ◽  
pp. 1217-1218 ◽  
Author(s):  
E. Charles Angell ◽  
Francesco Fringuelli ◽  
Ferdinando Pizzo ◽  
Lucio Minuti ◽  
Aldo Taticchi ◽  
...  
Keyword(s):  
Diels Alder ◽  
Cis And Trans

scholarly journals Synthesis of chiral anti-1,2-diamine derivatives through copper(I)-catalyzed asymmetric α-addition of ketimines to aldimines

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xu-Cheng Gan ◽  
Cheng-Yuan Zhang ◽  
Feng Zhong ◽  
Ping Tian ◽  
Liang Yin
Keyword(s):  
Nitro Group ◽  
Functional Groups ◽  
Phenyl Group ◽  
Asymmetric Reactions ◽  
Bioactive Molecules ◽  
Sandmeyer Reaction ◽  
Aryl Amine ◽  
Common Structure ◽  
Group A ◽  
High Yields

Abstract Chiral 1,2-diamines serve as not only common structure units in bioactive molecules but also useful ligands for a range of catalytic asymmetric reactions. Here, we report a method to access anti-1,2-diamine derivatives. By means of the electron-withdrawing nature of 2- or 4-nitro-phenyl group, a copper(I)-catalyzed asymmetric α-addition of ketimines derived from trifluoroacetophenone and 2- or 4-NO2-benzylamines to aldimines is achieved, which affords a series of chiral anti-1,2-diamine derivatives in moderate to high yields with moderate to high diastereoselectivity and high to excellent enantioselectivity. Aromatic aldimines, heteroaromatic aldimines, and aliphatic aldimines serve as suitable substrates. The nitro group is demonstrated as a synthetical handle by several transformations, including a particularly interesting Fe(acac)3-catalyzed radical hydroamination with a trisubstituted olefin. Moreover, the aryl amine moiety obtained by the reduction of the nitro group serves as a synthetically versatile group, which leads to the generation of several functional groups by the powerful Sandmeyer reaction, such as -OH, -Br, -CF3, and -BPin.

scholarly journals TiCl3 as a New Catalyst for the Imino Diels-Alder Reaction

2006 ◽  
Vol 1 (9) ◽  
pp. 1934578X0600100
Author(s):  
Narayan V. Mayekar ◽  
Sandip K. Nayak ◽  
Subrata Chattopadhyay
Keyword(s):  
Ambient Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Trans Isomers ◽  
Effective Catalyst ◽  
Diels Alder Reaction ◽  
Cis And Trans Isomers ◽  
Reaction Proceeds ◽  
Cis And Trans

Titanium(III) chloride was found to be an effective catalyst for the imino Diels-Alder reaction between an imine (generated in situ) and an activated alkene in acetonitrile at ambient temperature. The reaction proceeds smoothly to afford the corresponding adduct as a mixture of chromatographically separable cis- and trans isomers in moderate to good yields.

Assignment of configurations to adducts of 2-substituted anthracene with maleic anhydride by N.M.R. spectroscopy

1976 ◽  
Vol 29 (6) ◽  
pp. 1215 ◽  
Author(s):  
SM Verma ◽  
RM Singh
Keyword(s):  
Maleic Anhydride ◽  
Phenyl Group ◽  
Diels Alder ◽  
Amino Group ◽  
Restricted Rotation ◽  
Magnetic Effects ◽  
Anti Conformation ◽  
Diagnostic Probe

Isomeric adducts of 2-methylanthracene and maleic anhydride and of 2-aminoanthracene and maleic anhydride were prepared and their configurations determined by N.M.R. spectroscopy. The adducts were transformed into their N-aminoimide derivatives. N'-Substituents on the amino group were chosen so as to permit, because of their restricted rotation and non-planarity about the N-N' bond, an investigation into the magnetic effects of the cage moiety. When both the dienyl parts of the Diels-Alder adducts are almost identical, the N'-acetyl-N'-phenyl group has been found to be a diagnostic probe for the configurational studies. In N-(N'-acetyl-N'-aroy1amino)imide derivatives, the N'-aroyl group has been found to prefer an anti conformation while in the N?-acetyl- N'-phenyl group the N'-phenyl prefers the syn conformation.

scholarly journals Further Studies on the Pyrolytic Domino Cyclization of Stabilized Phosphonium Ylides Bearing an Ortho-Aminophenyl Group

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2153 ◽  
Author(s):  
R. Aitken ◽  
Lorna Murray ◽  
Alexandra Slawin
Keyword(s):  
Gas Phase ◽  
Phenyl Group ◽  
Phase Flow ◽  
Flow Conditions ◽  
X Ray ◽  
Benzyl Radicals ◽  
C And N

Four new, stabilized phosphonium ylides containing a 2-(benzyl(methyl)amino)phenyl group have been prepared and characterized and are found, upon pyrolysis under gas-phase flow conditions, to lose Ph3PO and benzyl radicals to afford new heterocyclic products resulting from domino cyclization of both C- and N-centered radicals. Most products arise from processes of the former type and have quinoline, phenanthridine, or ring-fused phenanthridine structures, while in one case, a process of the latter type leads to a benzocarbazole product. The X-ray structure of a 2-(methyl(tosyl)amino)phenyl ylide is also reported.

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