1028-12-2Relevant articles and documents
Synthesis and spin trapping kinetics of new alkyl substituted cyclic nitrones
Haire, D. L.,anzen, Edward G.
, p. 1514 - 1522 (1982)
Three new nitrones, 5-n-propyl-5-methyl-1-pyrroline-N-oxide (PMPO), 5-n-hexyl-5-methyl-1-pyrroline-N-oxide (HMPO), and 5-n-decyl-5-methyl-1-pyrroline-N-oxide (DeMPO), amphiphilic versions of the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), have been synthesized.A comparative study of the absolute rate constants for formation and decay of the tert-butoxyl spin adducts to these cyclic nitrones as well as 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (M4PO) has been undertaken using esr kinetic techniques.
Nucleophilic displacement reactions in ionic liquids: Substrate and solvent effect in the reaction of NaN3 and KCN with alkyl halides and tosylates
Chiappe, Cinzia,Pieraccini, Daniela,Saullo, Paola
, p. 6710 - 6715 (2003)
Room-temperature ionic liquids have been used as environmentally benign solvents for the preparation of primary and secondary alkyl azides and nitriles under solid-RTIL phase-transfer conditions. The reaction of primary, secondary, and tertiary halides or tosylates with KCN and NaN3 has been investigated in three ionic liquids ([bmim][PF6], [bmim][N(Tf) 2], and [hpyr] [N(Tf)2]). The observed nucleofugacity scales for the reaction of NaN3 are similar to those reported for the same process in cyclohexane, indicating that in these solvents it is possible to evidence the intrinsic ability to depart of leaving groups. Changes in the nature of the IL cation or anion determine significant modifications in reactivity of the investigated substrates. Reactivity has been interpreted considering a gradual shift of the mechanism from concerted SN2 (primary substrates) to stepwise SN1 (tertiary substrate, 3), through the nucleophilically assisted formation of an ion pair intermediate, in the case of 2d.
Practical and efficient methods for sulfonylation of alcohols using Ts(Ms)Cl/Et3N and catalytic Me3N · HCl as combined base: Promising alternative to traditional pyridine
Yoshida, Yoshihiro,Sakakura, Yoshiko,Aso, Naoya,Okada, Shin,Tanabe, Yoo
, p. 2183 - 2192 (1999)
Several alcohols were smoothly and practically tosylated by two methods A and B. Method A uses the TsCl/Et3N (1.5 - 2.5 equiv)/cat. Me3N · HCl (0.1 - 1.0 equiv) reagent. Compared with the traditional Py-solvent method, the method A has merits of its much higher reaction rate, operational simplicity, economy in the use of the amine, and circumvention of the undesirable side reaction from R-OTs to R-CL. Method B uses TsCl/KOH [or Ca(OH)2]/cat. Et3N (0.1 equiv)/cat. Me3N · HCl (0.1 equiv) as the reagent, which will be suited for practical and large scale production for primary alcohols. On both methods A and B, a clear joint action of Et3N and Me3N · HCl catalysts was observed. 1H NMR measurements support the proposed mechanism of the catalytic cycle. Related methanesulfonylation using Et3N and cat. Me3N · HCl in toluene solvent also successfully proceeded, wherein the clear joint action was also observed.
Ionic liquid brush as an efficient and reusable heterogeneous catalytic assembly for the tosylation of phenols and alcohols in neat water
Feng, Simin,Li, Jing,Wei, Junfa
supporting information, p. 4743 - 4746 (2017/07/12)
A very efficient and reusable heterogeneous ionic liquid brush assembly was developed. The catalyst exhibits high catalytic activity for the tosylation of phenols and alcohols in neat water. Moreover, the catalyst shows outstanding stability and reusability, and it can be simply and effectively recovered and reused five times without noticeable loss of catalytic activity.
A facile and green protocol for nucleophilic substitution reactions of sulfonate esters by recyclable ionic liquids [bmim][X]
Liu, Yajun,Xu, Yongnan,Jung, Sun Ho,Chae, Junghyun
supporting information, p. 2692 - 2698,7 (2012/12/12)
Ionic liquids [bmim][X] (X = Cl, Br, I, OAc, SCN) are highly efficient reagents for nucleophilic substitution reactions of sulfonate esters derived from primary and secondary alcohols. The counter anions (X-) of the ionic liquids, [bmim][X], effectively replace the sufonates affording the corresponding substitution products such as alkyl halides, acetates, and thiocyanides in excellent yields. The newly developed protocol is very environmentally attractive because the reactions use stoichiometric amounts of ionic liquids as sole reagents in most cases and do not require additional solvents, any other activating reagents, non-conventional equipment, or special precautions. Moreover, these ionic liquids can be readily recycled without loss of reactivity, making the whole process greener.
