Influence of Lewis acids on the Diels–Alder reaction. III. Rearrangement of dimethyl N-carbomethoxy-7-azabicyclo[2.2.1]2,5-heptadiene-2,3-dicarboxylate adducts to dimethyl N-carbomethoxy-3-aminophthalates

1970 ◽  
Vol 48 (9) ◽  
pp. 1472-1474 ◽  
Author(s):  
R. C. Bansal ◽  
A. W. McCulloch ◽  
A. G. McInnes

Aluminum chloride accelerates the Diels–Alder reactions of 2- or 2,5-substituted N-carbomethoxypyrroles with dimethyl acetylenedicarboxylate, and also catalyzes rearrangement of the N-carbomethoxy-7-azanorbornadiene adducts to 6- and 4,6-substituted dimethyl N-carbomethoxy-3-aminophthalates. Aromatization of the corresponding adduct of N-carbomethoxypyrrole only occurs on prolonged treatment with BF3. The procedure promises to be a convenient route for the synthesis of polysubstituted anilines.

1973 ◽  
Vol 51 (24) ◽  
pp. 4125-4136 ◽  
Author(s):  
A.W. McCulloch ◽  
D. G. Smith ◽  
A. G. McInnes

The Diels–Alder addition of furan to dimethyl acetylenedicarboxylate (DMAD) affords a monoadduct 1. The position and steric course of further addition of furan to the latter are temperature dependent. At temperatures of 50° or below addition occurs mainly at the activated double bond to give endo-endo4 and endo-exo5 diadducts. At 100° addition occurs at the less substituted double bond of the monoadduct to give analogous endo-endo7 and endo-exo9 diadducts; further addition of furan to the latter at 100° affords four triadducts 12–15. The configurations of all these products were determined by p.m.r. and assignments confirmed by simulation of the spectra.AlCl3 causes enormous rate enhancement of the Diels–Alder additions of furan to DMAD and to the activated double bond of the monoadduct. In the presence of the Lewis acid the predominant diadduct formed is the endo-exo isomer 5.


1969 ◽  
Vol 47 (13) ◽  
pp. 2391-2394 ◽  
Author(s):  
R. C. Bansal ◽  
A. W. McCulloch ◽  
A. G. McInnes

Depending on the experimental conditions the AlCl3-promoted reaction of 1-carbomethoxypyrrole and dimethyl acetylenedicarboxylate yields 2,3,7-tricarbomethoxy-7-azanorbornadiene, either in almost quantitative yield or together with dimethyl 1-carbomethoxy-2-pyrrolyl maleate and fumarate. The azanorbornadiene has been quantitatively converted to 1,4,5-tricarbomethoxyazepine via the corresponding 3-azaquadricyclane. The proton magnetic resonance spectra were analyzed with the aid of the Laocoon II program.


1978 ◽  
Vol 43 (19) ◽  
pp. 3727-3729 ◽  
Author(s):  
Chang Kiu Lee ◽  
Chi Sun Hahn ◽  
Wayland E. Noland

1971 ◽  
Vol 49 (19) ◽  
pp. 3152-3157 ◽  
Author(s):  
A. W. Mcculloch ◽  
A. G. McInnes

The AlCl3-promoted reactions of 2-methyl- and of 2-phenylfuran with ethyl propiolate afford as major products ethyl 5-hydroxy-2-methyl- and 2-phenylbenzoates (6a, 6b). Also isolated as minor by-products of these reactions are ethyl 3-(2-furyl-5-methyl)acrylate (5a), ethyl 3-(2-furyl-5-phenyl)acrylate (5b), ethyl 3,3-di(2-furyl-5-methyl)propionate (10a), ethyl 3,3-di(2-furyl-5-phenyl)propionate (10b), and ethyl 2-hydroxy-5-methylbenzoate (8a).


Heterocycles ◽  
1975 ◽  
Vol 3 (1) ◽  
pp. 85 ◽  
Author(s):  
Goro Kobayashi ◽  
Kzumichi Mizuyama ◽  
Yoshinori Miyake ◽  
Yoshinori Tominaga ◽  
Yoshiro Matsuda

2006 ◽  
Vol 84 (10) ◽  
pp. 1487-1503 ◽  
Author(s):  
Douglas P Heller ◽  
Daniel R Goldberg ◽  
Hongqiao Wu ◽  
William D Wulff

Several derivatives of the vaulted biaryl ligand VAPOL were prepared and evaluated as chiral ligands for aluminum Lewis acids in the catalytic asymmetric Diels–Alder reactions of methyl acrylate and methacrolein with cyclopentadiene. The substituents on VAPOL were introduced into the 6- and 6′-positions in an effort to further extend the chiral pocket of the major groove, which contains the phenol functions at the 4- and 4′-positions. The set of four new ligands that have been prepared have the following groups introduced into the 6- and 6′-positions of VAPOL: bromide, methyl, phenyl and 3,5-di-t-butylphenyl. All of these ligands give lower asymmetric inductions than the unsubstituted VAPOL for the Diels–Alder reactions of both methyl acrylate and methacrolein. The positive cooperativity of added carbonyl compounds on the autoinduction in the Diels–Alder reaction of methyl acrylate and cyclopentadiene were also investigated with the VANOL and VAPOL ligands as well as the 6,6′-dibromo and 6,6′-diphenyl derivatives of VAPOL. Only the reaction with VAPOL showed any significant positive cooperativity. The reaction with VANOL was sluggish at –78 °C, but at higher temperatures, the reaction did exhibit positive cooperativity that was similar to that of VAPOL. Finally, no positive cooperativity was observed with the VAPOL ligand for the reaction of methacrolein and cyclopentadiene.Key words: Diels–Alder, asymmetric catalysis, vaulted biaryl ligands, VANOL, VAPOL.


1991 ◽  
Vol 44 (8) ◽  
pp. 1085 ◽  
Author(s):  
JR Pearson ◽  
QN Porter

3-Vinylbenzofuran, 3-isopropenylbenzofuran and 2-methyl-3-vinylbenzofuran give normal [4π+2π] adducts with ethenetetracarbonitrile, accompanied, in the case of the last named diene, by the isomeric cyclobutane. Normal adducts also result from these dienes and 4-phenyl-1,2,4-triazoline-3,5-dione, and from 3-vinylbenzofuran and both maleic anhydride and N- phenylmaleimide. 3-Vinylbenzofuran gives the rearranged adduct dimethyl 1,2-dihydrodibenzofuran-3,4-dicarboxylate with dimethyl acetylenedicarboxylate.


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