Chlorotrimethylsilane Catalysed Acylation of Alcohols<sup>1</sup>

Kumareswaran, R.; Gupta, Aniket; Vankar, Yashwànt D.

doi:10.1080/00397919708005028

Cited by 55 publications

(21 citation statements)

References 12 publications

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“…Since these promoters strongly increase the electrophilicity of the anhydrides, their action is generally more efficient than the base activation 7. Therefore, in past years, considerable attention has been devoted to investigating the activity of a large variety of Lewis acids, such as CoCl 2 ,8 ZnCl 2 ,9 TiCl 4 /AgClO 4 ,10 Me 3 SiCl 11. More recently, it has been found that metal triflates are highly effective,12−14 even when loaded in trace amounts.…”

Section: Introductionmentioning

confidence: 99%

In the Twilight Zone between [2]Pseudorotaxanes and [2]Rotaxanes

Jeppesen

Vignon

Stoddart

2003

Chemistry A European J

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A [2]pseudorotaxane, based on a semi-dumbbell-shaped component containing asymmetrically substituted monopyrrolotetrathiafulvalene and 1,5-dioxynaphthalene recognition sites for encirclement by cyclobis(paraquat-p-phenylene) and with a "speed bump" in the form of a thiomethyl group situated between the two recognition sites, has been self-assembled. This supramolecular entity is a mixture in solution of two slowly interconverting [2]pseudorotaxanes, one of which is on the verge of being a [2]rotaxane at room temperature, allowing it to be isolated by employing flash column chromatography. These two [2]pseudorotaxanes were both characterized in solution by UV/Vis and (1)H NMR spectroscopies (1D and 2D) and also by differential pulse voltammetry. The spectroscopic and electrochemical data reveal that one of the complexes behaves wholly as a [2]pseudorotaxane, while the other has some [2]rotaxane character to it. The kinetics of the shuttling of cyclobis(paraquat-p-phenylene) between the monopyrrolotetrathiafulvalene and the 1,5-dioxynaphthalene recognition sites have been investigated at different temperatures. The shuttling processes, which are accompanied by detectable color changes, can be monitored using UV/Vis and (1)H NMR spectroscopies; the spectroscopic data have been employed in the determination of the rate constants, free energies of activation, enthalpies of activation, and the entropies of activation for the translation of cyclobis(paraquat-p-phenylene) between the two recognition sites.

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Section: Introductionmentioning

confidence: 99%

In the Twilight Zone between [2]Pseudorotaxanes and [2]Rotaxanes

Jeppesen

Vignon

Stoddart

2003

Chemistry A European J

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“…Given the importance of the reaction, in the last decades, CoCl 2 , 3 ZnCl 2 , 4 TiCl 4 -AgClO 4 , 5 Me 3 SiCl, 6 and various metal triflates [Sc(OTf) 3 , 7 Me 3 SiOTf, 8 In(OTf) 3 , 9 Cu(OTf) 4 , 10 and Bi(OTf) 3 ) 11 ] have been proposed to try to meet the continuous demand for more efficient and selective methods. The process is sluggish in the absence of an appropriate activator.…”

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confidence: 99%

Mg(ClO₄)₂as a Powerful Catalyst for the Acylation of Alcohols under Solvent-Free Conditions

Bartoli¹,

Bosco²,

Dalpozzo³

et al. 2002

Synlett

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“…A variety of catalysts have been used for activating this reagents, such as Sc(OTf) 3 and Sc(NTf 2 ) 3 [21], TiCl(OTf) 3 [22], TMSCl and TMSOTf [23], La(i-Pr) 3 [24], COCl 2 [25], Sn(OTf) 2 [26], TiCl 4 and AgClO 4 [27], AlPW 12 O 40 [28], PCl 3 -n(SiO 2 ) n [29], PPh 3 /CBr 4 [30] [32] and ZnO [33].…”

Section: Introductionmentioning

confidence: 99%