93638-77-8

Upstream product

• 118453-14-8 diethyl 2-(2-bromo-2-propenyl)-2-(2-propenyl)propanedioate 
• 101268-55-7 4,4-bis(ethoxycarbonyl)-1-hepten-6-yne 
• 3195-24-2 diallylmalonic acid diethyl ester 
• 2049-80-1 (2-propenyl)propanedioic acid diethyl ester 

Downstream Products

• 1225287-52-4 ethyl 2-ethoxycarbonyl-4-methyl-5-(2-methylphenyl)methyl-5-hexenoate 
• 1225287-64-8 ethyl 2-ethoxycarbonyl-2,4-dimethyl-5-phenylmethyl-5-hexenoate 
• 1225287-65-9 ethyl 2-benzoylmethyl-2-ethoxycarbonyl-4-methyl-5-phenylmethyl-5-hexenoate 
• 1225287-61-5 C₁₉H₂₅⁽²⁾HO₄ 
• 1225287-62-6 ethyl 2-ethoxycarbonyl-4-methyl-5-phenylmethyl-2-(2-propenyl)-5-hexenoate 
• 1225287-56-8 C₂₀H₂₈O₄ 
• 1225287-63-7 ethyl 2-ethoxycarbonyl-4-methyl-2,5-bis(phenylmethyl)-5-hexenoate 
• 1225287-49-9 ethyl 2-ethoxycarbonyl-4-methyl-5-phenylmethyl-5-hexenoate 
• 1225287-55-7 ethyl 2-ethoxycarbonyl-4-methyl-5-methylene-7-phenyl-7-octenoate 
• 1225287-53-5 ethyl 2-ethoxycarbonyl-5-(4-fluorophenyl)methyl-4-methyl-5-hexenoate 
• 1225287-50-2 ethyl 2-ethoxycarbonyl-4-methyl-5-(4-methylphenyl)methyl-5-hexenoate 
• 1225287-54-6 ethyl 2-ethoxycarbonyl-5-(4-ethoxycarbonylphenyl)methyl-4-methyl-5-hexenoate 
• 1225287-51-3 ethyl 2-ethoxycarbonyl-4-methyl-5-(4-methoxyphenyl)methyl-5-hexenoate 

Relevant academic research and scientific papers

A Free Radical Cyclization Catalyzed by Ruthenium Hydride Species

A photolytically generated ruthenium hydride species catalyzing a free radical cyclization reaction was developed. As the new methodology ensures reproducibility of the free radical reaction of trialkyltin hydrides and a fast hydrogen transfer to the radical intermediates, the methodology provides fast quenching of radical intermediates and thus suppresses rearrangement of radical intermediates before the hydride quench. By offering new reactivity and selectivity to the trialkyltin hydride mediated free radical cyclization reactions, the methodology will find wide range of applications in organic synthesis.

Iron(II) catalyzed reductive radical cyclization reactions of bromoacetals in the presence of NaBH4: optimization studies and mechanistic insights

5-Exo-trig radical reductive cyclization reactions of bromoacetals are catalyzed by iron in the presence of the reducing agent NaBH4. Both iron(II) and iron(III) were found to effectively mediate these reactions. As shown by cyclic voltammetry, iron(III) can be reduced to an iron(II) precatalyst before passing through an identical reaction mechanism in which monoelectronic activation of the substrate would occur by an anionic hydridoiron(I) complex. Further studies have established that both the substrate (iodo- vs bromo-derivative) and the precatalytic mixture are decisive in determining the reaction outcome.

Triarylphosphine ligands with hemilabile alkoxy groups: Ligands for nickel(II)-catalyzed olefin dimerization reactions. hydrovinylation of vinylarenes, 1,3-dienes, and cycloisomerization of 1,6-dienes

Substitution of one of the phenyl groups of triphenylphosphine with a 2-benzyloxy-, 2-benzyloxymethyl- or 2-benzyloxyethyl-phenyl moiety results in a set of simple ligands, which exhibit strikingly different behaviour in various nickel(II)-catalyzed olefin dimerization reactions. Complexes of ligands with 2-benzyloxyphenyl- and 2-benzyloxymethylphenyldiphenylphosphine (L5 and L6, respectively) are most active for hydrovinylation (HV) of vinylarenes, with the former leading to extensive isomerization of the primary 3-aryl-1-butenes into the conjugated 2-aryl-2-butenes even at -55 °C. However, 2-benzyloxymethyl-substituted ligand L6 is slightly less active, affording up to quantitative yields of the primary products of HV at ambient temperature with no trace of isomerization, thus providing the best option for a practical synthesis of these compounds. In sharp contrast, hydrovinylation of a variety of 1,3-dienes is best catalyzed by nickel(II) complexes of 2- benzyloxyphenyldiphenylphosphine, L5. The other two ligands, 2-benzyloxymethyl- (L6) and 2-benzyloxyethyldiphenylphosphine (L7) are much less effective in the HV of 1,3-dienes. Nickel(II)-catalyzed cycloisomerization of 1,6-dienes into methylenecyclopentanes, a reaction mechanistically related to the other hydrovinylation reactions, is also uniquely effected by nickel(II) complexes of L5, but not of L6 or L7. In an attempt to prepare authentic samples of the methylencyclohexane products, nickel(II) complexes of N-heterocyclic carbene ligands were examined. In sharp contrast to the phosphines, which give the methylenecyclopentanes, methylenecyclohexanes are the major products in the (N-heterocyclic carbene)nickel(II)-mediated reactions.

Medium-sized heterocycle synthesis by the use of synergistic effects of Ni-NHC and γ-coordination in cycloisomerization

This paper describes a new approach in transition-metal-catalyzed unsymmetric cycloisomerization for medium-sized heterocycles. The steric and electronic effects of an NHC-NiH catalyst and γ-heteroatom chelation were used together as a basis for 1,n-diene termini differentiation and for nγ-exo-trig (head-to-tail) product selectivity. Heterocycles bearing an exocyclic methylene such as oxepines, thiepines, siloxepines, and oxocanes were synthesized from the corresponding 1,n-dienes by a fine-tuning of the NHC properties. The implication of the underlying hypothesis was further demonstrated in a competition experiment in which strained oxepines were formed preferentially over other competing oxa-/carbocycles. Under more forcing physical conditions and the use of a suitable NHC ligand, the exocyclic methylene products were isomerized further into endocyclic olefin products regioselectively in one pot. (Chemical Equation Presented).

Triethylsilane-indium(III) chloride system as a radical reagent

(Chemical Equation Presented) A novel generation method of indium hydride (Cl2InH) was found by the transmetalation of InCl3 with Et3SiH. In the intramolecular cyclization of enynes, the previously reported system (NaBH4-InCl3) has a problem of side reactions with the coexistent borane. In contrast, the problem was solved by the presented system, which affords effective hydroindation of alkynes.

Diverging effects of steric congestion on the reaction of tributylstannyl radicals with areneselenols and aryl bromides and their mechanistic implications

The effects of bulky ortho,ortho' groups on the reactions of aryl bromides and areneselenols with tributylstannane have been studied. Bulky ortho,ortho' groups accelerate the reaction of the bromides with the stannane but retard the reactions of the selenols. On the other hand, ab initio and force field calculations show that introducing bulky ortho substituents into selenols causes a greater increase in strain than in the corresponding bromides. Two possible explanations for the divergent reactivity patterns are advanced. On one hand, it is possible that bromine abstraction by stannyl radicals from aryl bromides proceeds in a single step through a linear transition state whereas the abstraction of sell from the selenols involves a T-shaped, hypervalent intermediate. Alternatively, it may be that both reactions are concerted with the bromine abstraction having a late transition state and the sell abstraction an early one. Approximate second-order rate constants for the reaction of tributylstannane with a range of hindered aryl bromides are derived from competition reactions. 2,4,6-Tri-tert- butylbenzeneselenol is able to function moderately well as a catalyst for the stannane-mediated reactions of vinyl bromides. The X-ray crystal structure of bis(2,4,6-triisopropylphenyl) diselenide is presented.

Optimizing the 5-exo/6-endo ratio of vinyl radical cyclizations through catalysis with diphenyl diselenide

The 5-exo/6-endo product ratio in the stannane mediated cyclizations of vinyl iodides is very significantly improved by operating in the presence of catalytic PhSeSePh with no loss in overall cyclization yield.