Ethyl cyanoformate

Photolysis of 2,3-diphenyl-A -azirine (442) generates benzonitrile ylide (443). Irradiation in the presence of ethyl cyanoformate resulted in a mixture of the oxazoline (444) and the imidazole (445) by 1,3-dlpolar cycloaddition to the carbonyl and nitrile group, respectively (72HCA919). 

The photochemical addition of azirines to the carbonyl group of aldehydes, ketones, and esters is also completely regiospecific (77H(6)143). Besides the formation of the isomeric oxazolines (50) from (39) and ethyl cyanoformate, there is also formed the imidazole (51) from addition to C=N in the expected regioselective manner. Thioesters lead to thiazolines (52), while isocyanates and ketenes produce heterocycles (53). 

The (triphos)Ni0 template reacts with ethyl cyanoformate to give (220).648 The MO description and reactivity of the CS2 complex (221) has been studied in some detail.649 Treatment with 02 gives the dithiocarbonate compound (221a),650 while bubbling of C02 through a solution of (221) yields the carbonato complex (221b).651 In both cases, one of the phosphine arms has been oxidized and is found dangling. 

Cyclon Methyl Cyanoformate and Ethyl Cyanoformate Mixture CIO-A... 

Similar to reactions of iodopyrimidines previously mentioned in Section 6.2.2.2 (60 —> 61), the Grignard reagent 171, efficiently prepared from halopyridazine 170, was quenched with electrophiles such as acetaldehyde, ethyl cyanoformate, DMF or phenylsulfide to give 172 in acceptable yields <00T265>. 

The reaction of IV-alkyl- and iV-arylhydroxylamines with ethyl cyanoformate (193) leads to carbethoxyamino nitrones (194) (Scheme 2.68), which appear to be excellent starting materials for the synthesis of various nitrogen-bearing... 

The reactions of ethyl cyanoformate and dialkyl malonates in the presence of zinc chloride and triethylamine, or in the presence of TiCl4 or SnCl4 in methylene chloride at reflux temperature for 3 hr, or at room temperature overnight, gave amino(alkoxycarbonyl)methylenemalonates (314, R1 = Et) in good yields [79TL2525 81JAP(K)71050],... 

The transient C-nitrosoimine 193 (Ar = 4-CIC6H4) is formed by the action of ethyl cyanoformate on the sulfimide 191 and also by the oxidation of the amidoxime 192 with lead tetraacetate. In the presence of thebaine, both reactions yield an identical dihydrooxazine101. 

CuCN-2LiCl. This can then be selectively allylated vith allyl bromide to provide the dibromoimidazole 36, which can now be magnesiated by treatment with a further equivalent of iPrMgBr, providing the ester-substituted imidazole 37 in 55% yield after carboxylation with ethyl cyanoformate [25]. 

When ethyl cyanoformate was used as the cyanide source and a heterobimetallic YLi3(binaphthoxide) complex (YLB) (Figure 5.15) was used as catalyst, asymmetric cyanoethoxycarbonylations of aldehydes were achieved in high yields and enantioselectivities in the presence of three achiral additives water, tris(2,6-... 

In addition to metal catalysts, organocatalysts could also be used in asymmetric cyanation reactions. Chiral Lewis bases, modified cinchona alkaloids, catalyzed asymmetric cyanation of ketones by using ethyl cyanoformate as the cyanide source (Scheme 5.34)." Similar to metal-catalyzed reactions, ethyl cyanoformate was first activated by chiral Lewis bases to form active nucleophiles. Various acyclic and cyclic dialkyl ketones were transformed into the desired products. Because of using... 

The phenyliminothiatriazole 314 (R = Me, R =Ph) reacts with ethyl cyanoformate or p-toluensulphonyl cyanide to afford directly the phenyli-minothiadiazolines 316 (R = COOEt, p-MeC6H4S02) as a result of two consecutive reactions going through methylimino isomers 315 (91JHC333). In acetone solvent, the intermediate formation of the oxathiazolidine 317... 

In contrast, the 5-phenyliminothiatriazoline (323) reacts as a masked 1,3-dipole with a variety of electrophilic nitriles. Tosyl cyanide and ethyl cyanoformate both react with (323) in refluxing chloroform to give initially (324) which then isomerizes to (325) as the reaction proceeds (Scheme 71) <91JHC333>. When the solvent is changed to acetone the reaction with the nitriles proceeds faster due to the formation of the adduct (326) which is capable of undergoing cycloaddition/elimination reactions at 20 °C. Trichloroacetonitrile does not react with (323) in chloroform solution in acetone,... 

Dithiazolethiones (126) are thermally stable at least under reflux in xylene (see Section 4.14.5.2.1). However, on heating in the presence of DMAD or ethyl cyanoformate, the dithiol 2-thiones (127)... 

The submitters employed, without purification, ethyl cyanoformate purchased from Aldrich Chemical Company, Inc. 

Ethyl cyanoformate Formic acid, cyano-, ethyl ester (8) Carbonocyanidic acid, ethyl ester (9) (623-49-4)... 

The well-known application of 2,4,6-tris(ethoxycarbonyl)-l,3,5-triazine as a diene in inverse electron demand Diels-Alder cyclizations was adapted for the synthesis of purines <1999JA5833>. The unstable, electron-rich dienophile 5-amino-l-benzylimidazole was generated in situ by decarboxylation of 5-amino-l-benzyl-4-imidazolecarboxylic acid under mildly acidic conditions (Scheme 54). Collapse of the Diels-Alder adduct by retro-Diels-Alder reaction and elimination of ethyl cyanoformate, followed by aromatization by loss of ammonia, led to the purine products. The reactions proceeded at room temperature if left for sufficient periods (e.g., 25 °C, 7 days, 50% yield) but were generally more efficient at higher temperatures (80-100 °C, 2-24 h). The inverse electron demand Diels-Alder cyclization of unsubstituted 1,3,5-triazine was also successful. This synthesis had the advantage of constructing the simple purine heterocycle directly in the presence of both protected and unprotected furanose substituents (also see Volume 8). 

A transhydrocyanation reaction catalyzed by / / I INI. on Celite was investigated by Hanefeld and co-workers [41]. To shift the unfavorable equilibrium, the reaction was coupled with an irreversible acylation step. Problems occurred due to hydrolysis of the acyl donor by the water needed for enzyme activity and subsequent deactivation of the / Ihl I N1. by the acid formed. In situ derivatization in the cyanohydrin synthesis catalyzed by PaHNL on Celite was investigated, and a one-pot chemoenzymatic synthesis of protected cyanohydrins was developed using ethyl cyanoformate as both HCN donor and protecting reagent [70]. 

Compounds 98 behave as 1,3-dipoles in cycloaddition reactions with DMAD, ethyl cyanoformate, and alkenes the structure of the adduct 186 from ethyl cyanoformate suggests that reaction is via form 98b.131... 

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