4043-71-4

Usage

InChI:InChI=1/C4H5NO2S/c1-5-2-3(6)8-4(5)7/h2H2,1H3

Upstream product

• 78266-84-9 (1RS,2SR)-2-diphenylphosphinoyl-1-(3,4-methylenedioxyphenyl)propan-1-ol 
• 120-57-0 piperonal 
• 1530-32-1 ethyltriphenylphosphonium bromide 
• 94-58-6 dihydrosafrole 
• 64-19-7 acetic acid 
• 1135821-12-3 ethyl-(2-methoxy-phenyl)-diphenyl-phosphonium; iodide 
• 1135820-79-9 C₂₁H₂₂OP⁽¹⁺⁾*I^(1-) 
• 1135820-52-8 C₂₀H₂₀OP⁽¹⁺⁾*I^(1-) 
• 4736-60-1 ethyltriphenylphosphonium iodide 
• 24393-66-6 ethyl (E)-3-(benzo[d][1,3]dioxol-5-yl)acrylate 
• 58095-76-4 (E)-3-(benzo[d][1,3]dioxol-5-yl)prop-2-en-1-ol 
• 67911-75-5 (E)-5-(3-bromoprop-1-en-1-yl)benzo[d][1,3]dioxole 
• 75-03-6 ethyl iodide 
• 94-59-7 1-allyl-3,4-methylenedioxybenzene 

Downstream Products

• 94-53-1 Piperonylic acid 
• 134-38-3 4-benzo[1,3]dioxol-5-yl-5-methyl-[1,3]dioxane 
• 120-57-0 piperonal 
• 4676-39-5 1-(1,3-benzodioxol-5-yl)-2-propanone 
• 28281-49-4 3,4-methylenedioxypropiophenone 
• 6333-38-6 5-(3-methyl-oxiranyl)-benzo[1,3]dioxole 
• 132647-77-9 anthra[2,3-d;6,7-d']bis[1,3]dioxole-5,11-dione 
• 22688-82-0 (+/-)-5r-ethyl-7t-benzo[1,3]dioxol-5-yl-6c-methyl-6,7-dihydro-5H-indeno[5,6-d][1,3]dioxole 
• 17627-76-8 (Z)-5-(prop-1-en-1-yl)benzo[d][1,3]dioxole 

Relevant academic research and scientific papers

Iron Catalyzed Double Bond Isomerization: Evidence for an FeI/FeIII Catalytic Cycle

Iron-catalyzed isomerization of alkenes is reported using an iron(II) β-diketiminate pre-catalyst. The reaction proceeds with a catalytic amount of a hydride source, such as pinacol borane (HBpin) or ammonia borane (H3N?BH3). Reactivity with both allyl arenes and aliphatic alkenes has been studied. The catalytic mechanism was investigated by a variety of means, including deuteration studies, Density Functional Theory (DFT) and Electron Paramagnetic Resonance (EPR) spectroscopy. The data obtained support a pre-catalyst activation step that gives access to an η2-coordinated alkene FeI complex, followed by oxidative addition of the alkene to give an FeIII intermediate, which then undergoes reductive elimination to allow release of the isomerization product.

Highly Z-Selective Double Bond Transposition in Simple Alkenes and Allylarenes through a Spin-Accelerated Allyl Mechanism

Double-bond transposition in alkenes (isomerization) offers opportunities for the synthesis of bioactive molecules, but requires high selectivity to avoid mixtures of products. Generation of Z-alkenes, which are present in many natural products and pharmaceuticals, is particularly challenging because it is usually less thermodynamically favorable than generation of the E isomers. We report a β-dialdiminate-supported, high-spin cobalt(I) complex that can convert terminal alkenes, including previously recalcitrant allylbenzenes, to Z-2-alkenes with unprecedentedly high regioselectivity and stereoselectivity. Deuterium labeling studies indicate that the catalyst operates through a π-allyl mechanism, which is different from the alkyl mechanism that is followed by other Z-selective catalysts. Computations indicate that the triplet cobalt(I) alkene complex undergoes a spin state change from the resting-state triplet to a singlet in the lowest-energy C-H activation transition state, which leads to the Z product. This suggests that this change in spin state enables the catalyst to differentiate the stereodefining barriers in this system, and more generally that spin-state changes may offer a route toward novel stereocontrol methods for first-row transition metals.

Nickel-Catalyzed Allylic C(sp2)–H Activation: Stereoselective Allyl Isomerization and Regiospecific Allyl Arylation of Allylarenes

Stereoselective allyl isomerization and regiospecific allyl arylation reactions of allylarenes with a catalytic system comprising nickel(II) with an aryl Grignard reagent were studied. Both reactions are triggered by allylic internal C(sp2)–H activation by in-situ-formed Ni0, which is inserted into the C–H bond at the 2-position of the allyl moiety without a directing group. The isomerization of allylarene to 1-propenylarene favors the E isomer and proceeds with quantitative conversion. The arylation takes place through oxidative cross-coupling of allylarenes with excess Grignard reagent. It occurs regiospecifically at the position of C(sp2)–H activation and represents a new method for the synthesis of 1,1-disubstituted olefins. The results of deuterium labeling experiments reveal an alkenyl/alkyl mechanism involving allylic internal C(sp2)–H activation and multiple intermolecular 1,2-, 1,3-, and 2,3-hydride shifts. These methods represent new approaches to the functionalization of olefins, and the mechanistic investigations could be helpful for the discovery and design of new strategies for olefin functionalization.

Copper(I)-Catalyzed Allylic Substitutions with a Hydride Nucleophile

An easily accessible copper(I)/N-heterocyclic carbene (NHC) complex enables a regioselective hydride transfer to allylic bromides, an allylic reduction. The resulting aryl- and alkyl-substituted branched α-olefins, which are valuable building blocks for synthesis, are obtained in good yields and regioselectivity. A commercially available silane, (TMSO)2Si(Me)H, is employed as hydride source. This protocol offers a unified alternative to the established metal-catalyzed allylic substitutions with carbon nucleophiles, as no adaption of the catalyst to the nature of the nucleophile is required.

Photocatalytic synthesis of dihydrobenzofurans by oxidative [3+2] cycloaddition of phenols

We report a protocol for oxidative [3+2] cycloadditions of phenols and alkenes applicable to the modular synthesis of a large family of dihydrobenzofuran natural products. Visible-light-activated transition metal photocatalysis enables the use of ammonium persulfate as an easily handled benign terminal oxidant. The broad range of organic substrates that are readily oxidized by photoredox catalysis suggests that this strategy may be applicable to a variety of useful oxidative transformations.

Biphilic organophosphorus catalysis: Regioselective reductive transposition of allylic bromides via PIII/PV redox cycling

We report that a regioselective reductive transposition of primary allylic bromides is catalyzed by a biphilic organophosphorus (phosphetane) catalyst. Spectroscopic evidence supports the formation of a pentacoordinate (σ5-P) hydridophosphorane as a key reactive intermediate. Kinetics experiments and computational modeling are consistent with a unimolecular decomposition of the σ5-P hydridophosphorane via a concerted cyclic transition structure that delivers the observed allylic transposition and completes a novel PIII/PV redox catalytic cycle. These results broaden the growing repertoire of reactions catalyzed within the PIII/PV redox couple and suggest additional opportunities for organophosphorus catalysis in a biphilic mode.

Rhodium catalyzed aqueous biphasic hydroformylation of naturally occurring allylbenzenes in the presence of water-soluble phosphorus ligands

The rhodium-catalyzed hydroformylation of eugenol was performed in aqueous biphasic systems using various water soluble phosphines: TPPTS (triphenylphosphinetrisulphonated); BDPPETS (bisdiphenylphosphinoethanetetrasulphonated), BDPPPTS (bisdiphenylphosphi

Catalytic wittig reactions of semi- and nonstabilized ylides enabled by ylide tuning

The first examples of catalytic Wittig reactions with semistabilized and nonstabilized ylides are reported. These reactions were enabled by utilization of a masked base, sodium tert-butyl carbonate, and/or ylide tuning. The acidity of the ylide-forming proton was tuned by varying the electron density at the phosphorus center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity up to >95:5, E/Z. Time for a tune up: Catalytic Wittig reactions with semi- and nonstabilized ylides were enabled by use of a masked base (NaOCO2tBu) and/or ylide tuning. The acidity of the ylide-forming proton was tuned by varying the electron density at the P center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity.

METHODS FOR PHOSPHINE OXIDE REDUCTION IN CATALYTIC WITTIG REACTIONS

A method for increasing the rate of phosphine oxide reduction, preferably during a Wittig reaction comprising use of an acid additive is provided. A room temperature catalytic Wittig reaction (CWR) the rate of reduction of the phosphine oxide is increased due to the addition of the acid additive is described. Furthermore, the extension of the CWR to semi-stabilized and non-stabilized ylides has been accomplished by utilization of a masked base and/or ylide-tuning.

Ruthenium containing hydrotalcite as a solid base catalyst for >C{double bond, long}C< double bond isomerization in perfumery chemicals

Ruthenium containing hydrotalcite (Ru-Mg-Al) is used as a solid base catalyst for >C{double bond, long}C2 and Ru-alumina for isomerization of methyl chavicol to trans-anethole. Ru-Mg-Al catalyst was reused four times without loss in its activity, however, significant loss in the conversion of methyl chavicol and selectivity of trans-anethole was observed on reusability of other ruthenium impregnated catalysts. The conversion of methyl chavicol and selectivity of trans-anethole was found to increase on increasing the reaction temperature as well as amount of catalyst. At 0.005 g catalyst amount, 55% conversion of methyl chavicol with 68% selectivity of trans-anethole was observed that increased to 93% with 82% selectivity of trans-anethole at 0.05 g catalyst amount. On further increase in the amount of catalyst to 1 g, conversion increased to 98% with 88% selectivity of trans-anethole.