Allyltributyl stannane

Benzyloxyacetaldehyde Acetaldehyde, (phenylmethoxy)- (9) (60656-87-3) Allyltributylstannane Stannane, allyltributyl- (8) Stannane, tributyl-2-propenyl- (9) (24850-33-7)... 

As with the allylsilane cross-metathesis reactions, significant quantities of allyl stannane self-metathesis were not detected in any of the reactions and the trans isomer predominated in the cross-metathesis products. Identical reactions were carried out using allyltributyl stannane, in place of allyltriphenyl stannane, but the yields of the cross-metathesis products were consistently lower and in many cases dropped below 25%. 

Selenadiazoles are useful intermediates for the preparation of alkenes because they can be easily decomposed with the loss of nitrogen and a selenium atom under free radical conditions. However, if 1,2,3-selenadiazoles such as 102 are treated with allyltributyl stannane/AIBN in the presence of an olefin or diene dihydroselenophenes such as 103 are formed provided the 1,2,3-selenadiazole has been derived from a cyclic ketone. Under similar conditions 1,2,3-selenadiazoles prepared from linear or aromatic ketones afford alkynes as the sole products <02JOC 1520>. 

A Lewis acid-base complex, TiCl4-SbPh3, mediates the allylation of 2-(benzyloxy)propanal with allyltributyl-stannane, where a homoallyl alcohol is obtained with a high yy/z-selectivity (Equation (5)).40 The same complex is also effective for Diels-Alder reaction of an acrylate of (A)-ethyl lactate with cyclopentadiene, where an endo-adduct is formed predominantly with high diastereoselectivity and without polymerization of cyclopentadiene (Equation (6)). 

Unless otherwise specified, an equimolar mixture of two different aldehydes in CH2CI2 was treated with Danishefsky diene or 2-trimethylsiloxy)propene in the presence of ATPH (1—2 eq) at -78 C. Allylation was conducted using allyltributyl.stannane 5 mol% of ATPH at -78 C. 

Recent investigation of bis-Ti-allylpalladium 1-7, generated from allyltributyl-stannane and PdCl2(PPh3)2 (Scheme 2-40), afforded the cheraoselective functionalization of aldimines over aldehydes (Scheme 2-41) [79]. This unprecedented selectivity can be explained by the difference of the coordination ability between N and O atom to the transition metal. In general, the N-atom can coordinate to a transition metal more strongly. 

Keck [89a-c], Tagliavini [89d,e], and Yu [89f] have extensively studied the BINOL-Ti- or binol-Zr promoted reactions of achiral aldehydes with allylstan-nanes. The initial studies employed BINOL and either Ti(Oi-Pr)4 or TiCl2(0/-Pr)2 as the Lewis acid promoter in the reaction of achiral aldehydes with allyltributyl-stannane. The reaction affords good yields of the desired homoallylic alcohol with a high degree of enantioselectivity even with as little as 10 mol% of the chiral catalyst (Scheme 10-49) [89a]. The rate and turnover of the catalytic, asymmetric allylation reaction have also been optimized. It was found that when /-PrSSiMe3 is added to the reaction, a rate acceleration occurs, allowing as little as 1-2% of the catalyst to be used [89 fj. 

Table 12.19. Condensation of Allyltributyl Stannane with Cbiral Aldehydes (453)...

Asymmetric allylation of aldehydes with allyhc agents catalyzed by Lewis acid is a practical method for synthesizing optically active hranoallylic alcohols [10]. The chloro complex 1 serves as an efficient catalyst for asymmetric allylation of aldehydes with allylstannane [8, 9, 11]. In the presence of 5 mol% of the benzyl-phebox-Rh complex 1-Bn, the coupling reaction of benzaldehyde with allyltributyl-stannane in CH2CI2 at room temperature proceeded smoothly to provide the corresponding homo-aUyl alcohol 7a in 88% yield with 61% ee (Scheme 2). When methaUylstannane was subjected to the reactiOTi, enantioselectivity of the allylated product 8 significantly increased to be over 90% ee. 

Takemoto et al reported that ln(OTf)3 catalyzed the tandem allylation and cyclization of O-alkynylarylaldimines to form 1,2-dihydroisoquinolines, with a proton source to accelerate the rate of the reactions [233] (Figure 8.110). The authors proposed two pathways for the reaction, with the ln(OTf)3 functions either to activate the imine for an initial allylation followed by cyclization, or to activate the alkyne for cyclization followed by allylation. The authors also reported that nucleophiles other than allyltributyl stannane, notably silyl enol ethers, could also be used. 

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