Allylmagnesium compounds

The question of the solution structure of allyhnagnesium compounds is an intriguing one and such compounds have been studied in more detail by NMR than any other organomagnesium species. H and NMR data for selected allylmagnesium compounds are given in Tables 4 and 5, respectively. 

Allylmagnesium compounds appear to undergo a rapid allylic shift of the magnesium between the two methylene... 

Quinoxalines undergo facile addition reactions with nucleophilic reagents. The reaction of quinoxaline with allylmagnesium bromide gives, after hydrolysis of the initial adduct, 86% of 2,3-diallyl-l,2,3,4-tetrahydroquinoxaline. Quinoxaline is more reactive to this nucleophile than related aza-heterocyclic compounds, and the observed order of reactivity is pyridine < quinoline isoquinoline < phenan-thridine acridine < quinoxaline. ... 

Another example of a [2s+2sh-1c+1co] cycloaddition reaction was observed by Barluenga et al. in the sequential coupling reaction of a Fischer carbene complex, a ketone enolate and allylmagnesium bromide [120]. This reaction produces cyclopentanol derivatives in a [2S+2SH-1C] cycloaddition process when -substituted lithium enolates are used (see Sect. 3.1). However, the analogous reaction with /J-unsubstituted lithium enolates leads to the diastereoselective synthesis of 1,3,3,5-tetrasubstituted cyclohexane- 1,4-diols. The ring skeleton of these compounds combines the carbene ligand, the enolate framework, two carbons of the allyl unit and a carbonyl ligand. Overall, the process can be considered as a for-... 

Treatment of aromatic nitro compounds with allylmagnesium chloride, followed by 1.4 equiv. of LiAlH LAH) and a trace of palladium on charcoal affords hydroxylamines 387 (Ar = Ph, 4-CIC6H4, 2-FC6H4 or 3-MeOC6H4). If the amount of LAH is increased to 2.5 equiv. iV-allylarylamines 388 result. 1-Nitrohexane and nitrocyclohexane react analogously426. 

Diacid 54 was prepared by coupling a-a -di-bromo-m-xylene with allylmagnesium chloride, followed by Ru04-mediated cleavage of the resultant diene [29]. Diacid 54, prepared by an alternative route, was already a known compound Ruggli, P. Bucheler, P. Heb. Chim. Acta 1947, 30, 2048. 

Sphydrofuran is a structurally unique secondary metabolite produced by a variety of Streptomycetes strains. The first total synthesis of this compound was based in the use of RAMA to catalyze the aldol addition of chloroacetaldehyde with DHAP that provides two of the three chiral centers of the target molecule. The third quaternary center was introduced via a highly diastereoselective Grignard addition of allylmagnesium bromide (Scheme 4.17) [41]. 

Cyclic thiocarbonates, such as compound 169, react smoothly with allylmagnesium bromide. Careful control of the reaction conditions allows monoalkylation. Trapping of the intermediate sulfur anion with Mel provided the 1,3-dioxane in 78% yield (Equation 20) <2003H(59)87>. 

The reaction of allylmagnesium chloride with methylaluminium dichloride affords, after workup of the reaction mixture and recrystalUzation from THF, a rather unexpected compound (7), which, according to its crystal-strucmre determination, appears to consist of [(allyl)2Mg3Cl3(THF)6]+ cations and [(allyl)4Mg] anions in a 2 1 molar ratio (Figure 8). ... 

Allyltriphenyltin can also be prepared by using the reaction of preformed allylmagnesium bromide with triphenyltin chloride.2 However, the submitters prefer the simpler procedure described above for large-scale preparations of allyltin compounds. 

The octamethyldimolybdate(4—) anion can be prepared from the reaction of Mo2(02CCH3)4 and UCH3 in ether (114). The tetraallyldimolybdenum compound prepared by Wilke et al. (254) is also readily synthesized from tetraacetatodimolybdenum and allyllithium or allylmagnesium bromide (114). A... 

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