The Soluble Copper(I)-Catalyzed Decomposition of Dimethyl Diazomalonate and Di-<i>t</i>-butyl Diazomalonate in the Presence of Some Cycloalkenes

Peace, B. W.; Carman, F.; Wulfman, D. S.

doi:10.1055/s-1971-21790

Cited by 56 publications

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“…Methyl diazoacetate, methyl diazopropionate, and dimethyl diazo malonate were synthesized according to the described proce dures. [11][12][13] In this work we used Lewis acids Sc(OTf) 3 and Sn(OTf) 2 purchased from Acros Organics; EtAlCl 2 (0.8 M solution in hexane), GaCl 3 , Yb(OTf) 3 , and In(OTf) 3 from Aldrich. Dichloromethane was first kept over granulated KOH to bound HCl and then distilled over P 2 O 5 under dry argon.…”

Section: Resultsmentioning

confidence: 99%

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Reactions of diazo esters with electron-deficient alkenes in the presence of Lewis acids

et al. 2010

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Section: Resultsmentioning

confidence: 99%

“…14 Pyrazoline 1 (0.17 g, 90%) was obtained similarly from methyl diazoacetate (0.10 g, 1 mmol), methyl acrylate (0.17 g, 2 mmol), and Yb(OTf) 3 (36 mg, 0.06 mmol). 13 C NMR, δ: 17.2 (Me); 43.2 (C(4)); 52.2 and 52.9 (2 OMe); 69.1 (C(5)); 146.4 (C(3)); 162.2 (COO at C(3)); 171.9 (COO at C(5)).…”

Section: Resultsmentioning

confidence: 99%

Reactions of diazo esters with electron-deficient alkenes in the presence of Lewis acids

et al. 2010

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“…A mixture of 4,5-dihydro-2-morpholino(or -2-pyrrolidino)-3-thiophenecarbonitriles [8] (20 mmoles), dimethyl diazomalonate [9] (4.74 g, 30 mmoles) and rhodium(II) acetate dimer (80 mg, 0.18 mmole) in toluene (40 ml) was refluxed for 2 hours. After removal of the solvent in vacuo, the residue was purified by column chromatography on alumina with methylene chloride-acetone (4:1) as the eluent to give 1b,d,f,h.…”

Section: General Procedures For the Preparation Of 45-dihydrothiophenmentioning

confidence: 99%

“…The starting compounds dihydrothiophenium-1-bis(ethoxycarbonyl)methylides 1a,c,e,g were prepared by previously reported method [8]. Dihydrothiophenium-1-bis(methoxycarbonyl)-methylides 1b,d,f,h were synthesized by the reaction of the corresponding 2-amino-4,5-dihydro-3-thiophenecarbonitriles [8] with dimethyl diazomalonate [9] in the presence of rhodium(II) acetate dimer.When a mixture of sulfonium ylides 1a,c-h and sodium iodide (2 equivalents) in acetone was refluxed for 7 hours, the corresponding 3,4-dihydro-2H-thiopyrans 2a,c-h were obtained, and the expected ring opening products could not be isolated. In a similar manner, no reaction occurred in the case of 1b, and 1b was recovered unchanged.…”

mentioning

confidence: 99%

Synthesis of 3,4‐dihydro‐2h‐thiopyrans by the reaction of 4,5‐dihydrothiophenium‐1‐bis[ethoxy(and methoxy)carbonyl]methylides with sodium iodide

Maruoka¹,

Yamagata²,

Yamazaki³

2002

Journal of Heterocyclic Chem

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Sulfonium ylides 1a-h reacted with sodium iodide to afford the corresponding thiopyrans 2a-h. On the other hand, compounds 1a-d were treated with thionyl chloride to give the ring opening products 3a-d. The reaction of compounds 3a-d with sodium iodide and triethylamine provided the corresponding thiopyrans 2a-d. J. Heterocyclic Chem., 39, 217 (2002). Thiopyrans are attractive compounds for chemical synthesis because their similarity with pyrans hints at useful biological properties that should be relatively easy to discover due to their simple framework [1,2]. Rearrangement of sulfonium ylides is known to produce thiopyrans [3,4]. This paper presents a new synthesis of thiopyrans from sulfonium ylides. In the course of our studies on heterocyclic enaminonitriles, we have shown that the reactions of 2-amino-4,5-dihydro-3-furancarbonitriles with sodium iodide [5,6] or titanium(IV) chloride [7] proceed through an initial ring opening between the oxygen and the 5-position of the furan ring by the attack of a halide ion on the 5-position of the furan ring. Under the same conditions, in the case of the corresponding 4,5-dihydro-3-thiophene carbonitriles, ring opening reactions did not take place. In contrast with 4,5-dihydro-3-thiophenecarbonitriles, the sulfonium ylides 1 of 4,5-dihydro-3-thiophenecarbonitriles undergo cleavage at the sulfur-C-5 bond and subsequent recyclization in the presence of a base [8]. These findings suggest that the sulfur-C-5 bond of the sulfonium ylides is more easily cleaved than that of 4,5-dihydro-3-thiophenecarbonitriles. Hence, we examined the reaction of the sulfonium ylides with sodium iodide to see whether or not cleavage at the sulfur-C-5 bond takes place. The starting compounds dihydrothiophenium-1-bis(ethoxycarbonyl)methylides 1a,c,e,g were prepared by previously reported method [8]. Dihydrothiophenium-1-bis(methoxycarbonyl)-methylides 1b,d,f,h were synthesized by the reaction of the corresponding 2-amino-4,5-dihydro-3-thiophenecarbonitriles [8] with dimethyl diazomalonate [9] in the presence of rhodium(II) acetate dimer.When a mixture of sulfonium ylides 1a,c-h and sodium iodide (2 equivalents) in acetone was refluxed for 7 hours, the corresponding 3,4-dihydro-2H-thiopyrans 2a,c-h were obtained, and the expected ring opening products could not be isolated. In a similar manner, no reaction occurred in the case of 1b, and 1b was recovered unchanged. When N,N-dimethylformamide was used in place of acetone, compound 1b reacted with sodium iodide at 100°to provide 2b. Although ring expansion of thiophenes to thiopyrans via a process involving sulfonium ylide intermediates has been reported [3,4], to our knowledge, ring expansion of sulfonium ylides by use of sodium iodide has not been

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“…Procedure A: A mixture of 1 (5 mmol), dimethyl diazomalonate [11] (0.87 g, 5.5 mmol), and Rh 2 (OAc) 4 (0.02 g) in toluene (10 ml) was refluxed for 2h. The solvent was removed and the residue was purified by column chromatography on…”

Section: Reactions Of 1 With α-Diazocarbonyl Compounds (General Procementioning

confidence: 99%

Synthesis of 2H-Thiopyrans by Rhodium(II) Acetate-Catalyzed Reaction of 4-Amino-2,5-dihydro-3-thiophenecarbonitriles with α-Diazocarbonyl Compounds. Part 1

2000

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The transition-metal-catalyzed reactions of diazo compounds with various types of compounds containing sulfur atom have been extensively studied [1][2][3]. These reactions have been proposed to proceed through ylide formation by reactions of carbenoids derived from diazo compounds [4][5][6][7][8].We have already reported that 4,5-dihydro-3-thiophenecarbonitriles react with diethyl diazomalonate in the presence of copper powder to form stable 4,5-dihydrothiophenium-1-bis(ethoxycarbonyl)methylides [9]. In recent study, we showed that 4,5-dihydro-3-thiophenecarbonitriles react with ethyl diazoacetoacetate in the presence of rhodium(II) acetate to yield 1,4-oxathiocines [10]. The formation of the 1,4-oxathiocines involves initial generation of unstable sulfonium ylides which subsequently undergo a thermal rearrangement to give the observed products. In continuation of these studies we investigated the reactions of 2,5-dihydro-3-thiophenecarbonitriles 1 with α-diazocarbonyl compounds in the presence of rhodium(II) acetate in order to prove whether or not stable sulfonium ylides are formed. α-Diazocarbonyl compounds used in this study include dimethyl diazomalonate [11], methyl diazoacetoacetate [12], and ethyl diazobenzoylacetate [13].The starting compounds 2,5-dihydro-3-thiophenecarbonitriles 1a -c were synthesized by reaction of tetrahydro-4-oxo-3-thiophenecarbonitrile with morpholine, piperidine, and pyrrolidine in the presence of formic acid in ethanol (Scheme 1).Abstract. 4-Amino-2,5-dihydro-3-thiophenecarbonitriles 1 reacted with dimethyl diazomalonate in the presence of rhodium(II) acetate to give regioselectively 4-cyano-2H-thiopyrans 2 (C 2 -S insertion), and 5-cyano-2H-thiopyrans (C 5 -S insertion) were not isolated. Similar insertion was also obWhen a mixture of 2,5-dihydro-4-morpholino-3-thiophenecarbonitrile 1a, dimethyl diazomalonate, and a catalytic amount of rhodium(II) acetate in toluene was refluxed for 2h, dimethyl 4-cyano-2H-thiopyran-2,2-dicarboxylate 2a (C 2 -S insertion) was obtained in 63% yield, and the corresponding sulfonium ylide was not isolated (Scheme 2). Ando et al. have reported that the photolysis of dimethyl diazomalonate in 2,5-dihydrothiophene give dimethyl 3,6-dihydro-2H-thiopyran-2,2-dicarboxylate [14]. The mass spectrum and the results of elemental analysis of 2a indicate that 2a has the molecular composition C 14 H 18 N 2 O 5 S. The IR spectrum of 2a displays a band due to the non-conjugated ester carbonyl groups at 1740 cm -1 . The reaction was regioselective, and only one of the two possible regioisomers 2a and dimethyl 5-cyano-2H-thiopyran-2,2-dicarboxylate 2a' (C 5 -S insertion) was isolated.served in the reaction of 1 with methyl diazoacetoacetate and ethyl diazobenzoylacetate. The starting compounds 1 were synthesized by the reaction of tetrahydro-4-oxo-3-thiophenecarbonitrile with morpholine, piperidine, and pyrrolidine in the presence of formic acid in ethanol.

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The Soluble Copper(I)-Catalyzed Decomposition of Dimethyl Diazomalonate and Di-t-butyl Diazomalonate in the Presence of Some Cycloalkenes

Cited by 56 publications

References 0 publications

Reactions of diazo esters with electron-deficient alkenes in the presence of Lewis acids

Reactions of diazo esters with electron-deficient alkenes in the presence of Lewis acids

Synthesis of 3,4‐dihydro‐2h‐thiopyrans by the reaction of 4,5‐dihydrothiophenium‐1‐bis[ethoxy(and methoxy)carbonyl]methylides with sodium iodide

Synthesis of 2H-Thiopyrans by Rhodium(II) Acetate-Catalyzed Reaction of 4-Amino-2,5-dihydro-3-thiophenecarbonitriles with α-Diazocarbonyl Compounds. Part 1

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