On the Reaction of Isatin with Cyanomethylene(triphenyl)-phosphorane. A Nucleophilic Attack of Alkyl Phosphites on the Carbon–Carbon Double Bond of (E)-Oxindolylideneacetonitrile

Osman, F. H.; El-Samahy, Fatma A.

doi:10.1016/s0040-4020(99)01065-0

Cited by 30 publications

(13 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All the alkene products are characterized by 1 H, 13 that such Z-alkenes are difficult to make using other approaches. For example, with Wittig reaction strategy (isatin and ylide as substrates) the use of alkyl ylides gave poor yields and poor E/Z selectivities 36,37 In Knoevenagel-type condensation reactions between oxindole and alkyl aldehydes, E-selective alkene products were typically obtained 38 . The radical ring closure approach for this type of products also favours E-alkenes especially for alkyl alkyne substrates [39][40][41] .…”

Section: Resultsmentioning

confidence: 99%

Metal and carbene organocatalytic relay activation of alkynes for stereoselective reactions

et al. 2014

View full text Add to dashboard Cite

Transition metal and organic catalysts have established their own domains of excellence. It has been expected that merging the two unique domains should provide complimentary or unprecedented opportunities in converting simple raw materials to functional products. N-heterocyclic carbenes alone are excellent organocatalysts. When used with transition metals such as copper, N-heterocyclic carbenes are routinely practiced as strong-coordinating ligands. Combination of an N-heterocyclic carbene and copper therefore typically leads to deactivation of either or both of the two catalysts. Here we disclose the direct merge of copper as a metal catalyst and N-heterocyclic carbenes as an organocatalyst for relay activation of alkynes. The reaction involves copper-catalysed activation of alkynes to generate ketenimine intermediates that are subsequently activated by an N-heterocyclic carbene organocatalyst for stereoselective reactions. Each of the two catalysts (copper metal catalyst and N-heterocyclic carbene organocatalyst) accomplishes its own missions in the activation steps without quenching each other.

show abstract

Section: Resultsmentioning

confidence: 99%

Metal and carbene organocatalytic relay activation of alkynes for stereoselective reactions

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The synthesis and characterization of the carbamates C1–C4 has been reported previously 25 . The precursors for the synthesis of the carbamates, namely pre‐C5, 18 pre‐C6 26 and pre‐C7, 27 are known compounds and were prepared according to the methods detailed in previous publications. The carbamates C5–C7 were prepared from pre‐C5–C7 as detailed below.…”

Section: Methodsmentioning

confidence: 99%

Vasodilatory Activity of Novel Carbamate Derivatives of Isatin

Maronas

Sudo

Côrrea

et al. 2008

Clin Exp Pharma Physio

View full text Add to dashboard Cite

Isatin (1H-indole-2,3 dione) is an endogenous compound that may act as a physiological regulator of muscle contraction by reducing cGMP production by inhibition of guanylyl cyclase (GC) activity. Intracellular cGMP levels can regulate the contractile response of smooth muscle. Therefore, in the present study we investigated the effects of seven novel carbamate derivatives of isatin, namely C1-C7, on the contractility of aortic rings from Wistar rats. Carbamates C1 and C6 most effectively promoted endothelium-dependent relaxation of aortic rings pretreated with 10 micromol/L phenylephrine (PE) to induce contraction. The concentration of the C1 and C6 carbamates necessary to reduce PE-induced aortic contraction by 50% (IC(50)) was 5.6 +/- 1.0 and 48.4 +/- 3.4 micromol/L, respectively. Carbamate derivative-induced vasodilation required an intact endothelium, which is responsible for nitric oxide (NO) release. Pretreatment of rings with 100 micromol/L naloxone or 10 micromol/L atropine prevented the C1- and C6-mediated vascular relaxation, indicating that the vasodilatory activity was dependent on the activation of opioid or muscarinic receptors, respectively. The results of our studies provide insights into the role of novel carbamates in the regulation of vascular tone. Carbamates could stimulate NO synthesis, which induces vasodilation primarily by stimulation of GC and cGMP production. Taken together, our findings suggest that carbamate derivative-induced vasodilation may be considered an alternative treatment for primary and/or secondary hypertension.

show abstract

“…For example, the reaction of isatin (1а) with (cyanomethylidene)triphenylphosphorane resulted in the formation of electron-deficient oxindole 54 as a mixture of E-and Z-isomers, which further reacted with trialkylphosphites, forming dialkyl[cyano(2,3-dihydro-2-oxo-1H-indol-3-yl)methyl]phosphonate 55 and isomeric bis(indole)-containing cyclic phosphonates 56 (Scheme 24). 73 Osman and coworkers assumed that the initial reaction occurred between compound 54 and trialkylphosphite, followed by hydrolysis. 74 In our opinion, taking into account the facile hydrolysis of trialkylphosphites, the first step likely involved the formation of dialkylphosphite, followed by Pudovik reaction with compounds 54, forming structures 55 and 56 (Scheme 24).…”

Section: Scheme 22mentioning

confidence: 99%

“…81 A Wittig reaction of isatin (1a) with (ethoxycarbonylmethylidene)triphenylphosphorane with subsequent [1+2] cycloaddition reaction of (isopropylidene)triphenylphosphorane to compound 72a gave a spirocyclopropane derivative of indolin-2-one (73). 88 Reactions of isatins 1a,b with (acylmethylidene)triphenylphosphoranes in ethanol at room temperature occurred analogously, forming compounds 72 in high yields (Scheme 32).…”

Section: Scheme 27mentioning

confidence: 99%