Allyl tosylate

Allyl tosylate is also an excellent reactant (entry 2, Table 5.8), while allyl acetate is not under Cu(I)-catalyzed conditions. Not only saturated acylzirconocene chlorides, but also a,(3-unsaturated acylzirconocene chlorides give coupling products in good yields (entry 8, Table 5.8). Prenyl bromide also reacts with acylzirconocene chlorides under identical conditions to give a mixture of regioisomers (Scheme 5.30). However, a longer reaction time (10 h) is required for the completion of the reaction as compared to the reaction of allyl bromide (1 h). 

Dipropargyl ethers can be cyclized to isobenzofurane derivatives both in palladium or nickel catalysed transformations. In the former case dipent-2-ynyl ether was coupled with allyl tosylate to give the corresponding bicycle, albeit in poor yield.115 The same ring system was obtained in good yield in the nickel catalysed reductive cyclization of the diyne and the allene shown in 3.91... 

Alkyl sulfates, tosylates, and other esters of sulfuric and sulfonic acids can be converted to alkyl halides with any of the four halide ions.979 Neopentyl tosylate reacts with Cl, Br, or I without rearrangement in HMPA.980 Similarly, allylic tosylates can be converted to chlorides without allylic rearrangement by reaction with LiCl in the same solvent.981 Inorganic esters are intermediates in the conversion of alcohols to alkyl halides with SOCl2, PC15, PC13, etc. (0-67), but are seldom isolated. 

For a number of substrate classes these new AQN ligands are superior to the phthalazine-derived ones, that is, most vinylic and allylic compounds are dihydroxylated with significantly higher enantioselectivities. For example, using (DHQD)2AQN in the AD of allyl tosylate gives... 

The reactions of a-(arylsulfonyl)acetophenones with allylstannane in the presence of AIBN give a nearly 1 1 mixture of allyl tosyl sulfone and the corresponding ketone. NMR studies reveal the generation of tin enolate during the reaction course (Equation (S3)).238... 

Diastereoselective complexation of the latter cases (144a) proceeded with only modest selectivity for the former cases (144b) selectivity varied with solvent and temperatnre. The best case (dr, 97 3) ntilized a matched enantiopnre allyl tosylate with a menthyl ester anxiliary. Finally, in a few cases the addition of HFe(CO)3(NO) across diene has also proved snccesshil in the synthesis of (143). ... 

Allylic tosylates can be alkylated by Grignard reagents in the presence of a catalytic amount of Li2CuCl4 with a moderate selectivity in favor of the 8 2 product [49 Eq. (71)]. 

Neopentyl tosylate reacts with LiCl in HMPA and gives the chloride with clean inversion without rearrangement (equation 5). Another example of this reaction is the conversion of allylic tosylates to chlorides without rearrangement or reaction of the sensitive acetal (equation 6). Dimethylaminopy-ridine is a useful catalyst for the transformation of hydroxy compounds to chlorides with tosyl chloride. ... 

Mori et al. have shown that asymmetric alkylation with an allylic tosyl amide followed by a zirconium-promoted cyclization provides an efficient route to mesembrine and mesembrane alkaloids [107]. The best ee was obtained with BINAPO as the ligand. Scheme 28. The product was obtained in 86% ee and following recrystallization the sulfonamide was obtained in 99% ee. 

Oxazole 1 and 120 mol% allyl tosylate are stirred together in an oven-dried flask under N2 for the indicated time and temperature. The resulting viscous oil is triturated 3 times with 10 volumes of dry Et,0 and evaporated at 1 Torr to provide the dihydrooxazolium salt 2 which is used without further purification. 

Cycloadditions. When onl> i results in the formation of 9-subsun synthesized using allyl tosylates ai ligand allows 1-alkynes to participai... 

Allyl tosyl amides. Reaction of all) the corresponding halides (in situ) with amides. 

Ring enlargement of gam-dibromocyclopropanes cf. 4, 432-433). Tosylated medium-sized rings can be obtained in high yield by reaction of em-dibromo-cyclopropanes with this Ag(I) salt. A single product, an (E)-allylic tosylate, is obtained (disrotatory reaction). ... 

Benzannulation occurred by the reaction of allyl tosylate (225) and internal alkynes such as 3-hexyne to give the pentasubstituted benzene 227 in 93 % yield using Pd2(dba)3 and PPhs. The reaction is explained by repeated insertion of the triple bond to the TT-allylpalladium bond (228) to give 229 and 230. Subsequent intramolecular insertion affords 231. fi-R elimination provides the pentasubstituted benzene 227 via 232. No reaction occurred when allyl bromide or acetate were used. The trisubstituted benzene 233 was obtained by the reaction of 1-alkyne with allyl tosylate 225 when P(OPh)3 was used as a ligand [69]. 

The pyrrole anion behaves similarly. Moreover, the fraction of N-allylation product increases when allyl tosylate is used instead of the softer allyl bromide (134). 

For example, allylic alcohols, allylic esters, allylic halides, and allylic tosylates. 

Acetylenes are reduced to cis-olefins by NaBHi, and Fe(II)/lipoamide and Fe(II)/dithiol catalysts in ethanol, and further to alkanes by NaBH, /-polyethyleneglycol/PdCl2 Allylic tosylates are selectively desulfonylated with LiBHEt3 in the presence of PdCl2(dppp) without isomerisation. RhCl(PPh3)3 changes the direction of the hydroboration of hexenone from C=0 to C C addition (Scheme 4). ... 

Ruthenium Isomerises allylic alcohols to ketones the regiochemistiry was elucidated by deuteration studies.The Pd catalysed allylic rearrangement of allyl tosylates can be applied to the synthesis of a.p-unsaturated ketones. 

The j -BuLi-(—)-sparteine combination is widely used in enan-tioinductive organic reactions. 4.H7-i22 Benzylic asymmetric alkylation may thus be achieved by subsequent treatment with alkyl halides, alkyl tosylates, and allyl tosylates 1,3-Oxathiane derivatives shown in eq 50 may be lithiated and quenched with electrophiles. An interesting aspect of this reaction is the equatorial stereoselectivity, which is independent of the size of the electrophile introduced. ... 

---