Cyanocarbon Chemistry. IV.<sup>1</sup> Dicyanoketene Acetals

Middleton, W. J.; Engelhardt, V. A.

doi:10.1021/ja01544a054

Cited by 128 publications

(32 citation statements)

References 1 publication

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…nucleophilic substitution of alkoxide groups by NH,, primary and secondary amines (Scheme 21). Similar nucleophilic substitutions have also been observed with alkoxide ions [33]. Dicyanoketene cyclic acetals even act as alkylating agents towards amines, alkyl sulfides etc.…”

supporting

confidence: 65%

See 1 more Smart Citation

Reactions of Alkenediazonium Salts. Part 1. 2,2‐Diethoxyethene‐diazonium hexachloroantimonate: A diazonium, a carbenium or an oxonium salt?

Szele¹,

Tencer²,

Zollinger³

1983

Helvetica Chimica Acta

View full text Add to dashboard Cite

SummaryReactions of the title compound 1 with various nucleophiles have been studied. The salt behaves like an alkylating agent towards ethers, alcohols and water forming ethyl diazoacetate (2), which reacts further with excess of the nucleophile. A solvent cage mechanism accounting for the observed products is proposed. Thermal decomposition in inert solvents leads to the alkylation of the counter-ion, i.e. formation of chloroethane, and in anisole, alkylation and chlorination of the solvent are also observed.With a standard coupling component, 2-naphtholate ion, no azo coupling reaction of 1 is observed, but instead 14-methyl-14H-dibenzo [a,j]xanthene (17) is formed. The products of the reaction with diethylamine are diethylcyanoformamide (18) and ethyl diethylcarbamate (19). None of the chemistry of salt 1 is explained by the intervention of vinyl cations expected to be formed in a heterolytic dediazoniation. The predominant pathways seem to involve reactions of an oxonium salt (alkylating properties) or, in the case of diethylamine, a carbenium salt (primary nucleophilic attack on the p-C-atom of 1).The free energy barrier to C=C rotation in 1 is estimated to be 75 to 77 kJ/mol (18.0 to 18.5 kcal/mol), a value which falls between those expected for a double and a single bond.Introduction. -In the context of our investigations on the dediazoniation mechanism of aromatic diazonium ions'), comparisons with the reactivity of vinyldiazonium ions are interesting. Owing to their electronic similarity vinyldiazonium ions might be reagents for the formation of vinyl cations.The unsubstituted vinyldiazonium ion, H,C=CH-N,+, is not yet known. Therefore a theoretical study on the vinyldiazonium ion in the gas phase and in aqueous solution is a worthwhile undertaking. With others, we recently made such a study [2] for the gas phase by ab initio (STO-3G and 4-31G), and for solution by CND0/2 methods. This investigation is a continuation of previous theoretical

show abstract

supporting

confidence: 65%

“…The first step in Scheme 19 corresponds to a known reaction of ketene acetals [33] [34], for example 24, i.e. nucleophilic substitution of alkoxide groups by NH,, primary and secondary amines (Scheme 21).…”

mentioning

confidence: 99%

Reactions of Alkenediazonium Salts. Part 1. 2,2‐Diethoxyethene‐diazonium hexachloroantimonate: A diazonium, a carbenium or an oxonium salt?

Szele¹,

Tencer²,

Zollinger³

1983

Helvetica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…2,2-Dicyanoketene ethylene acetal was prepared according to the literature. [23] Poly(epichlorohydrin) (PEC), an atactic and amorphous Herclor H sample (Hercules Inc.), was purified by precipitation using CHCl 3 /CH 3 OH as solvent/non solvent system. Its molecular weight was M -w L 1.5 6 10 6 as derived from light scattering measurements (see further).…”

Section: Solvents Reagents and Precursor Polymermentioning

confidence: 99%

Matrix polarity effects on microphase separation in zwitterionomers, 1. Synthesis of the model random zwitterionomers

Bieglé

Galin²

2000

Macromol. Chem. Phys.

View full text Add to dashboard Cite

“…b) Quaternization of the amino precursors by the cyclic 2,2-dicyanoketene 1,2-ethylene acetal 25) (DCKEA) selectively leads with yields generally higher than 70% to the crystalline zwitterionic monomers AZ or Z2 depending on the stoichiometric ratio r = [DCKEA]/[A2 monomer] and on the solvent medium. For r = 0.45, the reaction performed in THF solution stops at the monozwitterion which crystallizes out of the solution.…”

Section: Monomer Synthesismentioning

confidence: 99%

“…1,3-bis(dimethylamino)-2-propanol (DMAP) was vacuum distilled over CaH 2 and stored under argon. Dicyanoketene ethylene acetal (DCKEA) was prepared according to the literature 25) . 2,29-Azoisobutyronitrile (AIBN) and benzoyl peroxide were recrystallized from methanol and chloroform-methanol, respectively.…”

Section: Solvents Salts and Reagentsmentioning

confidence: 99%

Towards highly functionalized and semi-rigid polyzwitterions, 1. Poly(dizwitterionic methacrylates): synthesis and specific properties

Bieglé

Mathis

Galin³

1999

Macromol. Chem. Phys.

View full text Add to dashboard Cite

as Z2 species) were synthesized by controlled quaternization of their diamino (A2) precursors with 2,2-dicyanoketene ethylene acetal (DCKEA). In absence of a spacer group (p = q = 0), free radical polymerization in homogeneous dimethyl sulfoxide (DMSO) solution is possible only for the AZ monomer but not for the Z2 one, as a result of steric hindrance in the latter case. In presence of a spacer group (p = 0, q = 1 and p = q = 1), polymerization of the Z2 monomers readily leads to high molecular weight polymers (degree of polymerization DP w A 10 3 ). The poly(dizwitterionic methacrylate) bearing the longer spacer group (p = q = 1) displays specific solution and bulk properties: a) solubility either in highly dipolar aprotic solvents with lower critical solution temperatures (N,N-dimethylacetamide (DMAC): 54 8C) and a "salting-in" effect of LiCl or in concentrated aqueous NaSCN solutions (L 3 mol N L

show abstract

Cyanocarbon Chemistry. IV.¹ Dicyanoketene Acetals

Cited by 128 publications

References 1 publication

Reactions of Alkenediazonium Salts. Part 1. 2,2‐Diethoxyethene‐diazonium hexachloroantimonate: A diazonium, a carbenium or an oxonium salt?

Reactions of Alkenediazonium Salts. Part 1. 2,2‐Diethoxyethene‐diazonium hexachloroantimonate: A diazonium, a carbenium or an oxonium salt?

Matrix polarity effects on microphase separation in zwitterionomers, 1. Synthesis of the model random zwitterionomers

Towards highly functionalized and semi-rigid polyzwitterions, 1. Poly(dizwitterionic methacrylates): synthesis and specific properties

Contact Info

Product

Resources

About

Cyanocarbon Chemistry. IV.1 Dicyanoketene Acetals

Cited by 128 publications

References 1 publication

Reactions of Alkenediazonium Salts. Part 1. 2,2‐Diethoxyethene‐diazonium hexachloroantimonate: A diazonium, a carbenium or an oxonium salt?

Reactions of Alkenediazonium Salts. Part 1. 2,2‐Diethoxyethene‐diazonium hexachloroantimonate: A diazonium, a carbenium or an oxonium salt?

Matrix polarity effects on microphase separation in zwitterionomers, 1. Synthesis of the model random zwitterionomers

Towards highly functionalized and semi-rigid polyzwitterions, 1. Poly(dizwitterionic methacrylates): synthesis and specific properties

Contact Info

Product

Resources

About

Cyanocarbon Chemistry. IV.¹ Dicyanoketene Acetals