Allyl iodide, reaction

Molybdenum trioxide acrolein formation, 30 152 allyl iodide reactions, 30 150 azopropene reactions, 30 150 Molybdenyl compounds, M=0 bond, 31 125 N-Monoalkylation, aniline derivatives, 38 249-252... 

Scheme 5. Azopropene and allyl iodide reactions over MOO3 at 32O C. From (20).

Place 56 g. of clean sodium, cut into small pieces, in a 500 ml. round-bottomed flask fitted with two 25 or 30 cm. double surface condensers in series. Weigh out 136 g. (72 ml.) of freshly distilled allyl iodide, b.p. 99-101° (Section 111,39). Introduce about one quarter of the aUyl iodide through the condensers. Warm the flask gently until the sodium commences to melt and immediately remove the flame. A vigorous reaction sets in and a liquid refluxes in the condensers. Add... 

Chelation control was postulated for the reaction between 2,3-[isopropylidenebis(oxy)] propanal and allyl iodide/stannous fluoride which proceeded with useful erythro selectivity92. 

In the presence of In powder 2-cycIohexen-l-one is converted by allyl iodide and Me3SiCI 14, in 63% yield, into the 1,4-addition product 2179 [84], which is also obtained in 73% yield by Sakurai 1,4-addition ofallyltrimethylsilane 82 to 2-cyclohexene-l-one in the presence of excess Me3SiCl 14 and catalytic amounts of InCl3 [85] (Scheme 13.25). Ytterbium] 111) triflate-catalyzed imino-ene reactions of N-tosylaldimines with a-methylstyrene are dramatically accelerated on addition of Me3SiCl 14 [85 a]. 

This reaction involves the two reactants carbon monoxide and alcohol and produces esters, or lactones. The starting material, which will be considered here, is an alkene or an alkyne but it is also possible to start from activated halides (aryl- or allyl- iodides and bromides) to produce the same kind of organic products. 

The authors have also studied the deprotection by less basic nucleophiles such as thiophenolate and iodide. Deprotection by the latter anion may lead to a side-reaction when condensation of the allyl iodide formed with the de-protected phosphorothioate leads to the corresponding S-allyl phosphoroth-ioate. To suppress this side reaction thiourea was used to trap the allyl iodide. 

Allyltin difluoroiodide, formed in situ by the oxidative addition of stannous fluoride to allyl iodide, is found to react with carbonyl compounds to give the corresponding homoallylic alcohols in excellent yields under mild reaction conditions (9). 

The allylic alkylation products represent useful synthons, as exemplified by the reaction sequence outlined in Scheme 10.4. For example, reductive ozonolysis of the allylic alkylation product 15 afforded the y-lactone 16 as a single diastereoisomer. Sequential alkylation with methyl iodide, and reductive alkylation using lithium naphthalenide with allyl iodide furnished the ternary-quaternary substituted y-lactones 17a/17b in 72% overall yield, as a 10 1 mixture of diastereomers favoring 17a [18]. This method provides a versatile approach to the construction of a variety of a-quaternary-/9-ternary stereogenic centers. 

Temperature programmed reaction (TPR) experiments were carried out by adsorbing allyl alcohol and allyl iodide on a 9.0 wt% Mo03/Si02 sample and monitoring the evolved products by mass spectrometry. The Raman spectra of the pure liquid reference compounds are shown in Fig. 2. They agree well with those reported earlier (18-20). 

The spectra of the adsorbed intermediates prior to reaction are shown in Fig. 3. The spectra show considerable differences from the solution reference spectra. The peaks for both surface species are also slightly different from each other, indicating differences in their structures. TPR traces of the main products are reported in Fig. 4. The complete TPD data were given earlier (27). In the case of allyl alcohol, there is formation of acrolein at relative low tenq>eratures. Only at high temperatures, 700 K, is there production of COx. In the case of allyl iodide the TPR spectra are considerably different. There is no production of acrolein, instead, only COx is formed at high temperatures, > 700 K. 

Figure 4. Temperature programmed reaction traces of adsorbed allyl alcohol and allyl iodide on Mo03/Si02.

Doyle et al. have demonstrated the catalyst-dependent diastereoselectivity in Rh(ii) complex-catalyzed reaction of cinnamyl methyl ether 36 and ethyl diazoacetate 35 (Scheme 6). " The change of the diastereoselectivity of the products 38a and 38b with different Rh(ii) catalyst provides strong evidence that Rh(ii) catalyst is associated with the ylide in the rearrangement process. The moderately high level of asymmetric induction (4-69% ee) is also observed with allyl iodide (Equation (4)). In this case, the chiral metal complex must be in the product-forming step, because free iodo ylide is achiral. 

When diphosphorous tetriodide is brought into contact with glycerin, an energetic reaction ensues, allylic iodide being formed —... 

The synthesis of yet another example begins with the allylation of the enamide (21-2) with methyl iodide. Reaction of this intermediate (23-1) as above with the ami-nopyrrazole (23-2) leads to the formation of the fused pyrimidinopyrrazole (23-3). This last productis is next acylated with thiazole-carboxillic acid (23-4) in the presence of aluminum chloride. There is thus obtained the sleep inducing agent indiplon (23-5) [24]. 

Homoallylic alcohols. Allyl iodide reacts wth SnF2 to form in situ allyltin difluoroiodidc, which reacts with aldehydes to form homoallylic alcohols in yields of 80-90%. The reaction with ketones proceeds in lower yield. l,3-Dimethyl-2-imidazolidinone is the most satisfactory solvent. SnCl2 and SnBr2 can be used, but yields are somewhat lower. 

Photolysis of allyl iodide in thiophene gives a mixture of 2-allyl- (63.8%) and 3-allyl-(36.2%) thiophenes (77JOC1570). This is in contrast to homolytic phenylation, where almost exclusive 2-phenylation takes place (Section 3.14.2.9). It has been suggested that the rate-determining step in the allyl substitution reaction has a small but definite charge-transfer character. 

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