Showing papers on "Diazomethane published in 1986"
TL;DR: The phosphaalkenes are derived from tris(trimethylsilyl)phosphine and acid chlorides, with acylphosphines considered as intermediates of the reaction as mentioned in this paper.
79 citations
TL;DR: It is proposed that such C-glycosyl compounds as 6a and 6b, which possess the diazoacetyl functional groups as their "aglycon", will be useful as enzyme-activated irreversible inhibitors (suicide substrates) of glycosidases, and as photoaffinity-labeling reagents and classical affinity-labelings reagents for carbohydrate-binding proteins.
41 citations
TL;DR: Spiropyrazolines have been synthesized by 1,3-dipolar cycloaddition of an 2-arylidene-1-tetralone, 3-arylide-chromanones, -1-thiochromanone, and -flavanones with diazomethane as discussed by the authors.
Abstract: Spiropyrazolines have been synthesized by 1,3-dipolar cycloaddition of an 2-arylidene-1-tetralone, 3-arylidene-chromanones, -1-thiochromanones, and -flavanones with diazomethane. The relative configuration and stereochemistry of the products have been determined by means of one-dimensional difference N.O.E. measurements. It is shown that ring-closure reaction is regioselective, yielding stereohomogeneous spiropyrazolines in one step.
25 citations
TL;DR: In this paper, a novel and efficient synthesis of 1-acylindoxyls (3) from 1-acelindoles (1) is described. The procedure involves the demethoxylation with stannic chroride of 1 -acyl-3-hydroxy-2-methoxy-indoline (2), which were obtained by the MoO5 oxidation of 1in methoanol.
Abstract: A novel and efficient synthesis of 1-acylindoxyls (3) from 1-acylindoles (1) is described. The procedure involves the demethoxylation with stannic chroride of 1-acyl-3-hydroxy-2-methoxy-indoline (2), which were obtained by the MoO5 oxidation of 1in methoanol. Since the MoO5 oxidation of 2-substituted 1-acylindoles (1f and 1g) gave not the corresponding indolines (2f and 2g), but 2-hydroxyindoxyls (4f and 4g), 2f and 2g were obtained by the methylation of 4f and 4g with diazomethane to give 5f and 5g, followed by the reduction of 5f and 5g with sodium borohydride, respectively.
25 citations
23 citations
22 citations
TL;DR: The heavily substituted Dewar benzene derivatives 3 and 5 merely yield the carboxylic acids 7 and 9 by loss of isobutene when heated to 150-200 °C; isomerization to the benzoic acid 8 is not at all observed.
22 citations
TL;DR: The stable monomer diphosphirane 2 is produced by the reaction of the diazomethane on the diphosphene 1, 2, this article,.
20 citations
TL;DR: In this article, a transcycloaddition reaction with cycloreversion and cyclopentadiene was used to give the angular adducts 7 n and 7 x, respectively.
19 citations
TL;DR: In this article, two dibenzazecine derivatives (8 and 9) were readily prepared as a mixture by a photochemical reaction of the bromophenolic compound (6).
Abstract: Two dibenzazecine derivatives (8 and 9) were readily prepared as a mixture by a photochemical reaction of the bromophenolic compound (6). Reduction of the mixture (8 and 9) with diborane followed by column chromatography on silica gel gave the secondary amine (11), which was converted into the diene derivative (12) by Birch reduction. Treatment of 12 with 5% hydrochloric acid, followed by O-methylation with diazomethane provided the homoerythrina base (1) in 21% yield.On the other hand, the base (1) was also prepared via Birch reduction of the amine (9). The mixture of the amides (8 and 9) was reduced directly with sodium in liquid ammonia and subjected to fractional crystallization to yield 13. On treatment with 5% hydrochloric acid, 13 produced the homoerythrina derivative (14), which was methylated with diazomethane to afford 15. Finally, the homoerythrina base (1) was obtained by reduction of the amide group in 15.
15 citations
TL;DR: In the presence of bases, even those (for example, pyridine) normally used for acylation reactions, 2 l -(2, 4 3 )-2,3, 4-tribenzoyloxycyclohex-5-enone or aromatic products can be obtained as mentioned in this paper.
TL;DR: The (cod)PtCl(CH3)(cod = cyclo-octa-1,4-diene) with diazomethane reaction as discussed by the authors, and the facile rearrangement of the latter to CH2CH3, may represent a model for the key steps in the title process.
Abstract: The reaction of (cod)PtCl(CH3)(cod = cyclo-octa-1,4-diene) with diazomethane to give (cod)Pt(CH3)(CH2Cl), and the facile rearrangement of the latter to (cod)PtCl(CH2CH3), may represent a model for the key steps in the title process.
TL;DR: The photochemical behavior of trimethylsilylbis(diisopropyl-amino)phosphine diazomethane, in the presence of trapping agents, suggests that γ3-phosphinocarbenes ( ) can be regarded as phosphorus vinyl ylides or λ5-phosphaacetylenes ( ).
Abstract: The photochemical behavior of trimethylsilylbis(diisopropyl-amino)phosphine diazomethane, in the presence of trapping agents, suggests that γ3-phosphinocarbenes ( ) can be regarded as phosphorus vinyl ylides or λ5-phosphaacetylenes ( ). The synthesis of various stable α-diazophosphorus derivatives is reported. Le comportement sous photolyse du trimethylsilylbis(diisopropyl-amino)phosphine diazomethane, en presence d'agents de piegeage. montre qu'un γ3-phosphinwarbene ( ) presente la reactivite d'un γ5-phosphaacetylene tres polarise ( ou ). La synthese de plusieurs derives stables comportant la fonction diazo en α d'un atome de phosphore est decrite.
TL;DR: The unsaturated heteronuclear dimetal complex [FeW(μ-CC 6 H 4 Me-4)(CO) 5 (η-C 5 Me 5 )] reacts with diazomethane to afford products corresponding to addition of either one or two methylene groups across the metal bond as mentioned in this paper.
TL;DR: The utility of the reaction between alkyl acrylates and diazomethane was investigated in this paper, where the whole homologous series of C1−C18n-alkyl-3-alkoxycarbonyl-2-pyrazolines migrate with binary systems containing benzene and ethyl acetate on Silufol.
TL;DR: A simple and sensitive method for the determination of N-nitrosomethylurea (NMU) in biological fluids was developed and successfully applied to the analysis of NMU in biological samples with some clean-up.
TL;DR: In this article, the role of diazomethane in carcinogenesis by nitrosamines was investigated and the second-order Moller-Plesset (MP2) energy barrier suggests that this exothermic reaction may proceed slowly.
Abstract: Recent work suggested that the role of diazomethane in carcinogenesis by nitrosamines should be reinvestigated. Ab initio self-consistent-field gradient calculations using a 4–21 G basis set have shown that on energetic grounds the involvement of diazomethane cannot be excluded. Diazomethane may be formed as a minor product in the presence of methanediazohydroxide and base. The transition structure for the direct formation of diazomethane from methanediazohydroxide is reported; the second-order Moller–Plesset (MP2) energy barrier suggests that this exothermic reaction may proceed slowly.
TL;DR: Chondroitin 6-sulfate, dermatan sulfate, and their methyl esters were depolymerized into mixtures of methylated, even-numbered oligosaccharides having a 4,5-unsaturated uronic acid, nonreducing end-group, respectively, with excess diazomethane in the presence of a small proportion of water.
TL;DR: In this paper, the trimethylsilylated cyclobut-3-ene-1,2-dicarboxylic acid anhydrides (2a-c) were obtained.
TL;DR: The first reported isolation of [6 + 4] dimers of a fulvene was reported in this article, where they were converted by silica gel to two dimers (12, 13 ) of 2-acetyl-6,6-dimethylfulvene epoxide.
TL;DR: The cyclopropanation of the double bonds in cyclooctatetraene by diazomethane in the presence of cuprous chloride is nonregioselective and leads to the formation of the corresponding mono-, di-, tri-, and tetracyclop-anation products.
Abstract: The cyclopropanation of the double bonds in cyclooctatetraene by diazomethane in the presence of cuprous chloride is nonregioselective and leads to the formation of the corresponding mono-, di-, tri-, and tetracyclopropanation products with yields determined by the amount of added diazomethane. The obtained bis-, tris-, and tetrakishomocyclooctatetraenes are characterized by a preference for the isomers with the exo orientation of the cyclopropane fragments.
TL;DR: It has been shown that the oxidation of larixol with chromic acid mixture forms methyl 6-oxo-8α,13α-epoxystroban-14β-oate, and 6,13-dioxo-14,15-bisnorlabd-7-en-17-oxide.
Abstract: It has been shown that the oxidation of larixol with chromic acid mixture forms methyl 6-oxo-8α,13α-epoxystroban-14β-oate, methyl 6-oxo-8α,13α-epoxystroban-14α-oate, and 6,13-dioxo-14,15-bisnorlabd-7-en-17-oate.
TL;DR: In this paper, the Gabriel reaction was used for the synthesis of non-fluorinated aziridine using cyclization of p-haloalkylamines, and it was shown that benzylamine adds smoothly to l, l,l,l-trifluoro-2-bromopropene to form $bromoalkylamine.
Abstract: Fluorinated aziridines are usually obtained by the addition of diazomethane at a C=N bond [i, 2] or nucleophilic elimination of fluorolefins [3] The synthesis of nonfluorinated aziridines is often carried out using the Gabriel reaction through cyclization of p-haloalkylamines In the present work, we have shown that benzylamine adds smoothly to l,l,l-trifluoro-2-bromopropene to form $-bromoalkylamine (I) This is the first report of the Gabriel cyclization of (I) for the synthesis of fluoroaziridine (II)~
Patent•
28 May 1986
TL;DR: In this paper, the reaction of a compound of formula III (R=H) such as 2-methyl-6-[ N-[ 2-(2-aminocarbonyl-3-methyl)butyl ]aminocarboxylic acid is allowed to react with 1-10 equivalent amounts of an aqueous alkali solution such as sodium hydroxide in 1-50% concentration at room temperature to 100 deg.
Abstract: NEW MATERIAL:A compound of formula I [m, n are 0-2 where m+n=2; p is 0, 1; R is H, dilower-alkylimino; R is 1-4C alkyl; R is 1-4C alkyl, 3-6C cycloalkyl; R and R may incorporate 3-6C cycloalkyl which may be substituted with 1-3C alkyl; X, Y are H, halogen, 1-4C alkyl; when m=0, n=2, or m=2, n=0, X, Y incorporate to form a ring of -(CH2)l- (l=3, 4)]. EXAMPLE:A compound of formula II. USE:Herbicide. PREPARATION:The reaction of a compound of formula III (R=H) such as 2-methyl-6-[ N-[ 2-(2-aminocarbonyl-3-methyl)butyl ]aminocarbonyl-thie ][ 2,3-b ]pyridine-5-carboxylic acid is allowed to react with 1-10 equivalent amounts of an aqueous alkali solution such as sodium hydroxide in 1-50% concentration at room temperature to 100 deg.C, when desired, treated with diazomethane to convert R into methyl, then ester-interchange reaction is conducted.