Arsonium Ylides Research Articles

Boron-Catalyzed C1 Copolymerization of Arsonium and Sulfoxonium Ylides toward Unrepresented Structures and Fluorescence Properties.

The first synthesis of well-defined poly(methylene-co-1,1-diphenylpropenenylene) (C1-co-C1'), equivalent to poly(ethylene-co-diphenylbutadiene) copolymers was accomplished by C1 copolymerization of novel diphenylpropenyl triphenyl arsonium ylides (Ph2AY) and dimethylsulfoxonium methylide (Me2SY) using B-thexylborepane as initiator. All polymerization conditions, including feed ratio, temperature, and reaction time, were optimized. A series of photoluminescent poly(ethylene-co-diphenylbutadiene)s were synthesized at different feed ratios, opening a new synthetic horizon for poly(ethylene-co-disubstitutedbutadiene) copolymers. Notably, a new C1 segment, arising from a double bond rearrangement, was confirmed by NMR, resulting in an unprecedented two-monomer three-structure random terpolymer. An unexpected red-shift phenomenon in the fluorescence spectra was observed with increasing the ratio of Ph2AY in the copolymer. This shift is attributed to the aggregation of diphenylbutadiene segment, similar to through-space conjugation (TSC), likely induced by a decrease in the crystallinity of copolymers. Furthermore, another disubstituted allylic triphenyl arsonium ylides, (E)-2-phenylbutenyl triphenyl arsonium ylide (MePhAY) was also synthesized and investigated. These additional compounds expand the knowledge and the potential applications of such copolymerization techniques in advanced materials.

Boron‐Catalyzed C1 Copolymerization of Arsonium and Sulfoxonium Ylides toward Unrepresented Structures and Fluorescence Properties

AbstractThe first synthesis of well‐defined poly(methylene‐co‐1,1‐diphenylpropenenylene) (C1‐co‐C1’), equivalent to poly(ethylene‐co‐diphenylbutadiene) copolymers was accomplished by C1 copolymerization of novel diphenylpropenyl triphenyl arsonium ylides (Ph2AY) and dimethylsulfoxonium methylide (Me2SY) using B‐thexylborepane as initiator. All polymerization conditions, including feed ratio, temperature, and reaction time, were optimized. A series of photoluminescent poly(ethylene‐co‐diphenylbutadiene)s were synthesized at different feed ratios, opening a new synthetic horizon for poly(ethylene‐co‐disubstitutedbutadiene) copolymers. Notably, a new C1 segment, arising from a double bond rearrangement, was confirmed by NMR, resulting in an unprecedented two‐monomer three‐structure random terpolymer. An unexpected red‐shift phenomenon in the fluorescence spectra was observed with increasing the ratio of Ph2AY in the copolymer. This shift is attributed to the aggregation of diphenylbutadiene segment, similar to through‐space conjugation (TSC), likely induced by a decrease in the crystallinity of copolymers. Furthermore, another disubstituted allylic triphenyl arsonium ylides, (E)‐2‐phenylbutenyl triphenyl arsonium ylide (MePhAY) was also synthesized and investigated. These additional compounds expand the knowledge and the potential applications of such copolymerization techniques in advanced materials.

Organoboron-mediated polymerizations.

The scientific community has witnessed extensive developments and applications of organoboron compounds as synthetic elements and metal-free catalysts for the construction of small molecules, macromolecules, and functional materials over the last two decades. This review highlights the achievements of organoboron-mediated polymerizations in the past several decades alongside the mechanisms underlying these transformations from the standpoint of the polymerization mode. Emphasis is placed on free radical polymerization, Lewis pair polymerization, ionic (cationic and anionic) polymerization, and polyhomologation. Herein, alkylborane/O2 initiating systems mediate the radical polymerization under ambient conditions in a controlled/living manner by careful optimization of the alkylborane structure or additives; when combined with Lewis bases, the selected organoboron compounds can mediate the Lewis pair polymerization of polar monomers; the bicomponent organoboron-based Lewis pairs and bifunctional organoboron-onium catalysts catalyze ring opening (co)polymerization of cyclic monomers (with heteroallenes, such as epoxides, CO2, CO, COS, CS2, episulfides, anhydrides, and isocyanates) with well-defined structures and high reactivities; and organoboranes initiate the polyhomologation of sulfur ylides and arsonium ylides providing functional polyethylene with different topologies. The topological structures of the produced polymers via these organoboron-mediated polymerizations are also presented in this review mainly including linear polymers, block copolymers, cyclic polymers, and graft polymers. We hope the summary and understanding of how organoboron compounds mediate polymerizations can inspire chemists to apply these principles in the design of more advanced organoboron compounds, which may be beneficial for the polymer chemistry community and organometallics/organocatalysis community.

Boron-Catalyzed Polymerization of Phenyl-Substituted Allylic Arsonium Ylides toward Nonconjugated Emissive Materials from C3/C1 Monomeric Units.

Two novel allylic arsonium ylide monomers with a phenyl (steric and electronic effect) group at different positions were synthesized and used in boron-catalyzed polymerization to produce a series of well-defined polymers, poly(2-phenyl-propenylene-co-2-phenyl-propenylidene) (P2-PhAY) and poly(3-phenyl-propenylene-co-3-phenyl-propenylidene) (P3-PhAY), with unusual structures but a controllable molecular weight and relatively low polydispersity. The backbone of these polymers consists of a mixture of C1 (chain grows by one carbon atom at a time) and C3 (chain grows by three carbon atoms at a time) monomeric units, as determined by 1H, 13C, and 1H-13C HSQC 2D NMR. Based on the experimental results and density functional theoretical (DFT) calculations, we were able to propose a mechanism that takes into account not only the steric hindrance, but also the electron effect of the phenyl group. In addition, a nontraditional intrinsic luminescence was observed from the nonconjugated P2-PhAY and P3-PhAY; such unexpected emission is attributed to the formation of C3-unit clusters, as evidenced by ultraviolet-visible and fluorescence spectroscopy.

High trans-Selectivity in Boron-Catalyzed Polymerization of Allylic Arsonium Ylide and its Contribution to Thermal Properties of C3-Polymers

The research reported in this publication was supported by the King Abdullah University of Science (KAUST) and Technology and by the Basque Government through grant IT1309-19.

A reaction of stabilized arsonium ylide of dicarboxylate ester with tropylium fluoroborate: An efficient strategy for ring contraction of cycloheptatriene

The coupling of vinylic ylide (3) synthesized from AsPh3 (2) and dimethyl acetylenedicarboxylate (DMAD) (1) with tropylium fluoroborate (4) in CH2Cl2 was found to give 3-phenyl-1,2-dicarbomethoxyprop-2-enylidentriphenyl arsonium salt (5) via ring contraction of cycloheptatriene. Treatment of the latter (5) with aqueous sodium hydroxide gives 3-phenyl-1,2-dicarbomethoxyprop-2-enylidentriphenylarsorane (6, Z-isomer), and this efficiently isomerized to E-isomer (7) under sunlight irradiation.

Terpolymers from Borane‐Initiated Copolymerization of Triphenyl Arsonium and Sulfoxonium Ylides: An Unexpected Light Emission

AbstractThe first synthesis of well‐defined poly[(phenylmethylene‐co‐methylpropenylene)‐b‐methylene, [(C1‐co‐C3)‐b‐C1], terpolymers was achieved by one‐pot borane‐initiated random copolymerization of ω‐methylallyl (C3 units, chain is growing by three carbon atoms at a time) and benzyltriphenylarsonium (C1 units, chain is growing by one carbon atom at a time) ylides, followed by polymerization of sulfoxonium methylide (C1 units). Other substituted arsonium ylides, such as prenyltriphenyl, propyltriphenyl and (4‐fluorobenzyl)triphenyl can also be used instead of benzyltriphenylarsonium. The obtained terpolymers are well‐defined, possess a predictable molecular weight and low polydispersity (Mn,NMR=1.83–9.68×103 g mol−1, Đ=1.09–1.22). An unexpected light emission phenomenon was discovered in these non‐conjugated terpolymers, as confirmed by fluorescence and NMR spectroscopy. This phenomenon can be explained by the isomerization of the double bonds of allylic monomeric units along the chain of the terpolymers (isomerization‐induced light emission).

Terpolymers from Borane-Initiated Copolymerization of Triphenyl Arsonium and Sulfoxonium Ylides: An Unexpected Light Emission.

The first synthesis of well‐defined poly[(phenylmethylene‐co‐methylpropenylene)‐b‐methylene, [(C1‐co‐C3)‐b‐C1], terpolymers was achieved by one‐pot borane‐initiated random copolymerization of ω‐methylallyl (C3 units, chain is growing by three carbon atoms at a time) and benzyltriphenylarsonium (C1 units, chain is growing by one carbon atom at a time) ylides, followed by polymerization of sulfoxonium methylide (C1 units). Other substituted arsonium ylides, such as prenyltriphenyl, propyltriphenyl and (4‐fluorobenzyl)triphenyl can also be used instead of benzyltriphenylarsonium. The obtained terpolymers are well‐defined, possess a predictable molecular weight and low polydispersity (Mn,NMR=1.83–9.68×103 g mol−1, Đ=1.09–1.22). An unexpected light emission phenomenon was discovered in these non‐conjugated terpolymers, as confirmed by fluorescence and NMR spectroscopy. This phenomenon can be explained by the isomerization of the double bonds of allylic monomeric units along the chain of the terpolymers (isomerization‐induced light emission).

Boron-Catalyzed C3-Polymerization of ω-2-Methyl Allylarsonium Ylide and Its C3/C1 Copolymers with Dimethylsulfoxonium Methylide.

A novel arsonium ylide, ω-2-methylallylarsonium ylide, was synthesized and used as monomer for polyhomologation with triethyborane as initiator. It was found that the terminal methyl group leads to C3 polymerization. Furthermore, the copolyhomologation of arsonium ylide with dimethylsulfoxonium methylide is reported for the first time.

Stereoselective synthesis of sulfonyl-substituted trans-2,3-dihydrofuran derivatives via reaction of arsonium Ylides with α,β-unsaturated ketones

Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1+4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 in CH2Cl2 in the presence of potassium carbonate at room temperature. The structures of the products were characterized by IR, MS, 1H NMR, elemental analysis and single crystal X-ray diffraction analysis. A mechanism for the formation of products was also proposed.

Highly Stereoselective Cyclopropanation of Olefins Catalyzed by a Novel C 3-Symmetric Arsine

A novel C 3-symmetric arsine was employed in the one-pot cyclopropanation of olefins with carbonyl-stabilized arsonium ylides formed in situ from phenacyl bromide in the presence of NaHCO3. This new arsine demonstrates good stereoselectivity and activity in the one-pot cyclopropanation of arylidenemalononitrile. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]

Solvent-Free Stereoselective Synthesis of Chalcones via Wittig Reaction of Arsonium Ylide by Grinding

A solvent-free process for the stereoselective preparation of chalcones by grinding is described. Its advantages are easy workup, mild reaction conditions, high yields, and environmental friendliness.

Effect of Novel Superplasticizer on Workability and Strength of Ready Mixed Concrete

With the advent of superplasticizers, dream to discover method of making ready mixed concrete at the lowest possible water cement ratio while maintaining a high workability has achieved. In addition, these concrete material are also suitable for use with other cementations materials like fly ash. Poly(styrene-co-acrylonitrile) prepared with the help of p-acetyl benzylidene triphenyl arsonium ylide had made it possible, the production of concrete at low water cement ratio. Many waste materials of today become the useful by products of tomorrow water cement ratio was maintained between 0.38-0.47. Use of fly ash in concrete improves the penetration rate of CO 2 or chloride ions. The result have shown substantial improvement in the properties of concrete after use of copolymer of styrene and acrylonitrile as superplasticizer.

Synthesis of a novel C3-symmetric arsine and its application in stereoselective cyclopropanation of electron-deficient olefins

A novel C3-symmetric arsine was synthesized from p-arsanilic acid in three steps. It was employed in the one-pot cyclopropanation of olefins with carbonyl-stabilized arsonium ylides formed in situ from methyl bromoacetate in the presence of NaHCO3. This new arsine demonstrates good stereoselectivity and activity in the one-pot cyclopropanation of arylidenemalononitrile.

ChemInform Abstract: A Convenient Synthesis of Fluorine‐Containing trans‐1,2‐Cyclopropane Derivatives from Semistabilized Arsonium Ylides.

The fluorine-containing trans-1,2-cyclopropane derivatives 4ba–4dd were synthesized from the fluorine-containing electron-deficient alkenes 3a–3d with semistabilized arsonium ylides 2b–2d, in biphasic system of dichloromethane-50% aqueous sodium hydroxide, generated in situ from the corresponding arsonium salts 1b–1d at room temperature in good yields with high stereoselectivity. The structure of fluorine-containing trans-1,2-cyclopropane derivatives were also studied.

Fullerene as radical inhibitor in polymerization of acrylonitrile initiated by arsonium ylide

Kinetics of polymerization of acrylonitrile (AN) in presence of fullerene (C60) has been studied using p-acetyl benzylidine triphenyl arsonium ylide as initiator in dioxane at 60 ± 0.1°C under the blanket of nitrogen. The rate of polymerization (R p ) at low concentration of fullerene may be represented as R p ∝ [Ylide]0.5[AN]1.0 [Full]−0.6, indicating inhibition effect of fullerene on the polymerization. The energy of activation for the polymerization was found to be 71.5 ± 0.5 kJ mol−1. Fourier transform infrared spectroscopic analysis (FTIR) confirmed the insertion of fullerene in to the final polymer. The mechanism for the polymerization has also been proposed.

An efficient and highly stereoselective synthesis of novel trifluoromethylated trans-dihydrofuro[2,3-c]pyrazoles using arsonium ylides

An efficient approach of highly stereoselective synthesis of novel trifluoromethylated trans-4,5-dihydrofuro[2,3-c]pyrazoles has been described. Arsonium bromides 1 reacted smoothly with the electron-deficient alkenes (Z)-4-aryl-1-phenyl-3-(trifluoromethyl)-1H-pyrozol-5(4H)-ones 2 to give products trans-dihydrofuro[2,3-c]pyrazoles 3 with high stereoselectivity and in good to excellent yields, using CH2Cl2 as solvent and K2CO3 as base.

A Convenient Synthesis of Fluorine‐Containing trans‐1,2‐Cyclopropane Derivatives from Semistabilized Arsonium Ylides

AbstractThe fluorine‐containing trans‐1,2‐cyclopropane derivatives 4ba–4dd were synthesized from the fluorine‐containing electron‐deficient alkenes 3a–3d with semistabilized arsonium ylides 2b–2d, in biphasic system of dichloromethane‐50% aqueous sodium hydroxide, generated in situ from the corresponding arsonium salts 1b–1d at room temperature in good yields with high stereoselectivity. The structure of fluorine‐containing trans‐1,2‐cyclopropane derivatives were also studied.

One-Pot Synthesis of Novel Photochromic Oxazine Compounds

A one-pot domino synthesis of photochromic 2,2-diarylphenanthro-(9,10)-[2H]-[1,4]-oxazines in excellent yield is described starting with acrylic acid derivatives. The reaction mechanism was studied by ReactIR and UV-vis. The cascade sequence of the reactions involves five transformations, namely, acyl azide formation, Curtius rearrangement, arsonium ylide formation, aza-Wittig, and final cyclization to the title compounds.

ChemInform Abstract: Highly Stereoselective Synthesis of trans‐4‐Trifluoromethylsulfonyl‐2,3‐dihydrofurans from Arsonium Ylides and (E)‐α‐Trifluoromethylsulfonyl‐α,β‐unsaturated Ketones.

AbstractThe reaction tolerates a wide range of functional groups at the arsonium ylides and a variety of aromatic and furanyl substituents at the α,β‐unsaturated ketones and proceeds with complete stereoselectivity.