Organophosphine as an Alkyl Transfer Shuttle for the Direct β-Alkylation of Chalcones Using Alkyl Halides
5
Citation
28
Reference
10
Related Paper
Citation Trend
Abstract:
We report an efficient alkyl transfer strategy for the direct β-alkylation of chalcones using commercially available alkyl bromides as alkyl reagents. In this transformation, the ortho-phosphanyl substituent in the chalcones is crucial for controlling their reactivity and selectivity. It also serves as a reliable alkyl transfer shuttle to transform electrophilic alkyl bromides into nucleophilic alkyl species in the form of quaternary phosphonium salts and transfer the alkyl group effectively to the β-position of the chalcones. This alkyl transfer strategy can be further extended to the alkenylation of ortho-phosphanyl benzaldehydes to assemble functionalized polyenes.Keywords:
Phosphonium
Beta-Hydride elimination
A new procedure for alkylating dihydrolysergic acid (1) on the indole nitrogen is reported. Previous procedures involved reaction of the indoyl anion with an alkyl halide. As the alkyl group gets larger, dehydrohalogenation of the alkyl halide becomes the preferred reaction and little or no N 1-alkylation occurs. By using alkyl tosylates in place of alkyl halides, we have been able to alkylate 1 on the indole nitrogen with a wide variety of alkyl groups in high yield.
Dehydrohalogenation
Beta-Hydride elimination
Cite
Citations (11)
Phosphonium
Cationic polymerization
Superacid
Dication
Ylide
Cite
Citations (22)
Alkylation of the aza-enolate of valerolactim methyl ether with electrophiles affords α-alkyl lactims that may be hydrolysed under mild acidic conditions to afford their corresponding α-alkyl-δ-amino esters as their hydrochloride salts. Neutralisation of these salts with base results in smooth intramolecular cyclisation to afford their corresponding α-alkyl lactams in excellent yield.
Beta-Hydride elimination
Hydrochloride
Williamson ether synthesis
Cite
Citations (3)
The physicochemical properties of two novel ionic liquids based on benzyltriethylphosphonium and benzyltributylphosphonium cations are described in this report. It was found that both benzyl-substituted phosphonium cations gave low-melting salts in combination with a bis(trifluoromethylsulfonyl)amide anion. The thermogravimetric analysis suggested that the benzyl-substituted phosphonium ionic liquids showed higher thermal stability than those of not only the alkyl-substituted phosphonium ILs but also the corresponding benzyl-substituted ammonium compounds. The benzyl-substituted phosphonium ionic liquids also exhibited relatively high conductivities when compared to those of the corresponding ammonium compounds. These results indicate an improving effect of introducing a benzyl group into the phosphonium cations on both the thermal stability and the conductivity.
Phosphonium
Thermal Stability
Thermogravimetric analysis
Amide
Cite
Citations (63)
The physicochemical and electrochemical properties of room-temperature ionic liquids based quaternary phosphonium cations together with tetracyanoborate anion are presented in this report. It was found that the tetracyanoborate anion based phosphonium ionic liquids showed relatively low viscosity, high conductivity and considerably high thermal stability when compared to those of the corresponding ammonium and the conventional phosphonium ionic liquids. The introduction of a methoxy group into the phosphonium cation tended to reduce the thermal stability and the electrochemical stability of the ionic liquids.
Phosphonium
Thermal Stability
Cite
Citations (4)
Structure and Bonding in Phosphonium Ylides, Salts and Phosphoranes Preparation, Properties and Reactions of Phosphonium Salts Preparation, Properties and Reactions of Phosphoranes Structure, Bonding and Spectroscopic Properties of Phosphonium Ylides Electrochemistry of Phosphonium Salts, Phosphoranes and Ylides Chemical Analysis of Organophosphorous Compounds.
Phosphonium
Phosphonium salt
Cite
Citations (5)
Abstract We show that phosphonium azolide ionic liquids of interest for CO 2 capture applications react with CO 2 both through the normal anion channel and, at elevated temperatures, through a previously unrecognized cation channel. The reaction is caused by an interaction between the anion and cation that allows proton transfer, and involves a phosphonium ylide intermediate. The cation reaction can be mitigated by using ammonium rather than phosphonium cations. Thus, phosphonium and ammonium cations paired with aprotic heterocyclic anions (AHAs) react with CO 2 through different mechanisms at elevated temperatures. This work shows that careful consideration of both physical properties and chemical reactivity of ILs based on AHA anions is needed when designing ionic liquids for CO 2 separations.
Phosphonium
Reactivity
Ylide
Cite
Citations (64)
Abstract The Catellani reaction has received substantial attention because it enables rapid multiple derivatization on aromatics. While using alkyl electrophiles to achieve ortho ‐alkylation was one of the earliest applications of the Catellani reaction, ipso ‐alkylation‐terminated reactions with β ‐H‐containing reactants has not been realized to date. Herein, we report alkylation‐terminated Catellani reaction using alkyl carbagermatranes (abbreviated as alkyl‐ Ge ) as nucleophiles. The reactivity of alkyl‐ Ge and alkyl‐B(OH) 2 in this reaction is discussed. This approach enables efficient dialkylation with β ‐H‐containing reactants, which was previously inaccessible by Catellani reactions.
Reactivity
Cite
Citations (6)
Coupling reaction
Beta-Hydride elimination
Cite
Citations (11)
A series of hitherto unknown hetaryl-substituted (in phosphonium part) phosphonium-iodonium ylides were synthesized. The reaction of these mixed phosphonium-iodonium ylides with acetylenes opens a way to new furyl annelated phosphinolines or unusually substituted phosphininofurans.
Phosphonium
Cite
Citations (27)