Preparative nucleophilic substitution with "betylates". Substrate phase transfer and substrate-reagent ion-pair reactions

King, J. F.; Loosmore, Sheena M.; Lock, J. D.; Aslam, Mohammad

doi:10.1021/ja00473a069

Cited by 16 publications

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“…If we may apply the same factor to the ionization of 6 then we obtain 4 x lop2 s-I for acetolysis of 6 at 25°C. This estimate, though very rough, is remarkably close to the rate constant, 3 x s-I, that we may calculate from the acetolysis rates of the tosylate and triflate taken with of, values given in Table 3; using o;C, = 2.13 for trifluoromethyl (as discussed) gives 5 x lo-' s-' for the acetolysis of the [Olbetylate (6). Though the approximations made in this analysis are both many and crude, the results are in full agreement with the mechanism in Scheme 2.…”

Section: Prediction Of the Rates Ofreaction Of [O]supporting

confidence: 70%

“…In this context rapid formation of the primary alkyl fluorosulfates (3) from the ion-pair (2) is entirely expected in view of the high nucleofugality predicted for the [Olbetylate grouping. It should perhaps be pointed out, however, that the fluorosulfate salts of 1-alkyl [2]betylates have not, in our hands, given 1-alkyl fluorosulfates, but rather the di-1-alkyl sulfates (6). These are believed to arise via the comparatively rapid hydrolysis of the fluorosulfate anion by adventitious moisture, followed by SRIP reactions with the bisulfate and alkylsulfate betylate ionpairs.…”

Section: Reaction Of Alkyl Nn-dimethylsulfamates (1)mentioning

confidence: 66%

“…The latter conversion may be regarded as a "substrate-reagent ion-pair'' (SRIP) reaction (6), a process we have found in the reactions of [2]-and [3]betylates to be a surprisingly facile process, even for anions of very low nucleophilicity. The perchlorate or trifluoromethanesulfonate (triflate) salts of 1-hexadecyl [2]betylate, for example, are converted almost quantitatively into 1-hexadecyl perchlorate or 1-hexadecyl triflate, respectively, by refluxing in toluene for one hour (6). In this context rapid formation of the primary alkyl fluorosulfates (3) from the ion-pair (2) is entirely expected in view of the high nucleofugality predicted for the [Olbetylate grouping.…”

Section: Reaction Of Alkyl Nn-dimethylsulfamates (1)mentioning

confidence: 99%

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Betylates. 2. The formation and high reactivity of alkyl [0]betylates

King¹,

Lee²

1981

Can. J. Chem.

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. Can. J. Chem. 59,362 (1981). Unhindered primary alkyl N,N-dimethylsulfamates (1) react with methyl fluorosulfate to give the corresponding alkyl fluorosulfates (3) and the betaine, M~,&so,-(4), evidently by way of the intermediate alkyl [Olbetylate fluorosulfate (2); with certain other alkyl esters (1) products of substitution, elimination, and rearrangement are formed. The reaction not only provides a potentially useful route to simple alkyl fluorosulfates, but serves to demonstrate the powerful nucleofugality of the [Olbetylate group. To obtain a method for predicting the reactivity of [Olbetylates, we have compared substituent parameters with rate constants in four series of nucleophilic displacements involving esters of the general structure ROS02Z; correlation (of log k) with o* is mediocre but a new parameter, o : , with a "15% resonance" contribution as defined by Swain and Lupton, gives good to excellent agreement in the four reaction series. Evidence is presented for formation of the 7-norbornyl cation via the [Olbetylate from 7-norbornyl N,N-dimethylsulfamate and methyl fluorosulfate. Comparison with what is known of the reactivities of 7-norbornyl p-toluenesulfonate and trifluoromethanesulfonate esters serves to confirm that [0] betylates are among the most nucleofugal functions of which a derivative has been fully characterized.JAMES FREDERICK KING et TERESA MEE-LING LEE. Can. J. Chem. 59,362 (1981). Introduction more reactive than even the "super sulfonates". In the accompanying paper (1) we have reported Accordingly when we had determined that an aryl that phenyl N,N-dimethylsulfamate reacts with [Olbet~late could be prepared from an aryl N,Nmethyl fluorosulfate to yield the first example of an dimethylsulfamate, we quickly turned our attention isolable "[Qlbetylate" (i.e. trialkylammoniosul-to the corres~onding reaction of alkyl N,Nfate) ester.2 dimethylsulfamates. This paper describes our study of this reaction and our observation of the

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Section: Prediction Of the Rates Ofreaction Of [O]supporting

confidence: 70%

Section: Reaction Of Alkyl Nn-dimethylsulfamates (1)mentioning

confidence: 66%

Section: Reaction Of Alkyl Nn-dimethylsulfamates (1)mentioning

confidence: 99%

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Betylates. 2. The formation and high reactivity of alkyl [0]betylates

King¹,

Lee²

1981

Can. J. Chem.

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“…We have recently pointed to the merits of betylates (1) and norbetylates (2) as intermediates in the conversion of alcohols into other classes of compounds by way of nucleophilic substitution (1)(2)(3)(4)(5). involving ten primary or secondary alkyl groups and more than thirty different nucleophiles, leading to such varied products as halides, azides, thiocyanates, sulfonium salts, and carboxylate, sulfonate, and perchlorate esters.…”

mentioning

confidence: 99%

“…(a) Hexadecyl3-phenylthio-1-propanesulforzate (18a) 3-Phenylthio-1-propanesulfonyl chloride (17) (5 .O1 g, 20 mmol) and 1-hexadecanol (4.36 g, 18 mmol) in CC1, (150 mL) and triethylamine (4.04 g, 40 mmol) in 80 mL of CC1, gave a white solid (7.76 g, 95%), which was recrystallized from pentane, mp 40°C; ir v,,,: 2910 (s), 2840 (s), 1465 (w), 1430 (w), 1345 (m), 1 150 (s), and 955 (w) cm-'; 'H nmr (CDCl?) 6: 0.88 (t, 3H),1.26 (s, 26H), 1.45-1.76 (m, 2H), 2.15 (quintet, 2H), 3.07 (t, 2H), 3.27 (t, 2H), 4.19 (t, 2H), 7.27-7.41 (m, 5H); ms M+ calcd. : 456.2731; found: 456.2723.…”

mentioning

confidence: 99%

Betylates. 4. The synthesis and preparative nucleophilic substitution reactions of alkyl S-[3]betylates

King¹,

Skonieczny²,

Poole³

1983

Can. J. Chem.

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Alkyl S-[3]betylates (S,S-dialkyl-S-3[(alkyloxy)sulfonyl]propylsulfonium salts), the first examples of S-betylates (sulfonioalkanesulfonic esters), have been synthesized by two routes, and their suitability as intermediates in the transformation of alcohols by nucleophilic substitution reactions examined. They have been found to react readily in stoichiometric phase transfer processes, including substrate–reagent ion-pair reactions, like their previously studied nitrogen analogues, with the following particular features: (a) they may be used with basic nucleophiles (unlike [2]betylates), (b) they are more simply made from commercially available starting materials than [3]betylates, and (c) they can be made by a route that avoids a final alkylation step.

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