58568-17-5

Upstream product

• 5978-08-5 1-chloro-4-(1,3-dioxolane)-n-pentane 
• 100-52-7 benzaldehyde 
• 133549-41-4 C₇H₁₃LiO₂ 

Downstream Products

• 58568-24-4 6-Phenyl-6-chlorhexanon-2 

Relevant academic research and scientific papers

Fundamental Difference in Reductive Lithiations with Preformed Radical Anions versus Catalytic Aromatic Electron-Transfer Agents: N,N-Dimethylaniline as an Advantageous Catalyst

The reductive lithiation of phenyl thioethers, or alkyl chlorides, by either preformed aromatic radical anions or by lithium metal and an aromatic electron-transfer catalyst, is commonly used to prepare organolithiums. Revealed herein is that these two methods are fundamentally different. Reductions with radical anions occur in solution, whereas the catalytic reaction occurs on the surface of lithium, which is constantly reactivated by the catalyst, an unconventional catalyst function. The order of relative reactivity is reversed in the two methods as the dominating factor switches from electronic to steric effects of the alkyl substituent. A catalytic amount of N,N-dimethylaniline (DMA) and Li ribbon can achieve reductive lithiation. DMA is significantly cheaper than alternative catalysts, and conveniently, the Li ribbon does not require the removal of the oxide coating when DMA is used as the catalyst.

Reductive Lithiation in the Absence of Aromatic Electron Carriers. A Steric Effect Manifested on the Surface of Lithium Metal Leads to a Difference in Relative Reactivity Depending on Whether the Aromatic Electron Carrier Is Present or Absent

One of the most widely used methods of preparation of organolithium compounds is by the reductive lithiation of alkyl phenyl thioethers or, usually less conveniently, alkyl halides with either aromatic radical-anions of lithium or lithium metal in the presence of an aromatic electron-transfer catalyst. Here we present results showing that lithium dispersion can achieve reductive lithiation in the absence of the electron-transfer agent. This procedure is more efficient, and surprisingly, the order of reactivity of substrates is reversed depending on whether the electron-transfer agent is present or absent. For example, in the presence of a preformed radical-anion, tert-butyl phenyl sulfide cleaves significantly faster than methyl phenyl sulfide, whereas in the absence of the radical-anion, it is just the opposite. Density functional theory calculations reveal that the exothermicity of the cleavage of the C-S bond in alkyl phenyl thioethers on the lithium surface is dependent on the size of the alkyl group, the smaller the alkyl group the greater the exothermicity. The increased reactivity is attributed to the smaller steric repulsion between the alkyl group and the lithium surface. The methodology includes, but may not be limited to, the lithium dispersion reductive lithiation of phenyl thioethers, alkyl chlorides, acrolein diethyl acetal, and isochroman.

ROMPgel-supported biphenyl and naphthalene: Reagents for lithiation reactions with minimal purification

The synthesis of ring opening metathesis, polymer (ROMPgel) supported naphthalene and biphenyl reagents was carried out. These reagents were utilized for catalytic lithiation reactions of aryl and alkyl chlorides and for the reductive deprotection of benzyl and allyl ethers.

Polyphenylene as an electron transfer catalyst in lithiation processes

The lithiation of different functionalised chlorinated materials (1a-c), dichlorinated compounds (1d-f) and benzofused cyclic ethers (1g,h) with lithium powder in the presence of catalytic amounts of either linear (LPP) or crosslinked (CPP) polyphenylene, in THF at temperatures ranging between -78 and 20°C, leads to the expected organolithium intermediates (Ia-h), which by reaction with electrophiles [ButCHO, PhCHO, Et2CO, (CH2)5CO, PhCOMe, Me3SiCl] gives, after hydrolysis with water, the expected products 2aa-hf.

Polymer supported arene-catalysed lithiation reactions

The reaction of functionalised mono or dichlorinated materials 1a-6a with an excess of lithium and a catalytic amount of a naphthalene (P(N)) or biphenyl (P(B)) supported polymer (easily prepared by radical copolymerisation of 2-vinylnaphthalene or 4-vinylbiphenyl with vinylbenzene and divinylbenzene) in THF either in the presence or not of different electrophiles [Me3SiCl, (i)prCHO, PhCHO, Et2CO, (CH2)4CO, (CH2)5CO, (c- C3H5)2CO, (i)Pr2CO, PhCOMe, PhCH=NPh] at -78 or -50°C leads, after hydrolysis with water, to the expected functionalised products 1ca-6ck. The polymeric catalyst is quantitatively recovered and can reused several times without any loss of activity.

Masked Lithium Bishomoenolates: Useful Intermediates in Organic Synthesis

The lithiation of the chloro ketals 9 with lithium naphthalenide at -78 deg C led to the corresponding masked lithium bishomoenolates 4, which are stable species under these conditions and react with different electrophilic reagents (H2O, D2O, i-PrCOH, Ph

2-(3-Lithiopropyl)- and 2-(3-lithiopropyl)-2-methyl-1,3-dioxolane: New masked lithium bishomoenolates in the synthesis of bifunctionalized compounds

2-(3-Lithiopropyl)- and 2-(3-lithiopropyl)-2-methyl-1,3-dioxolane (2) are prepaned by lithiation of the corresponding chlorinated precursors with lithium naphthalenide at -78°C. The reaction of these masked bishomoenolates with different electrophiles yie