Study on the removal of olefins from naphtha by clay loaded with trifluoromethanesulfonic acid

Author(s):  
Zheng Wu ◽  
Xuan Meng ◽  
Li Shi ◽  
Naiwang Liu
Synthesis ◽  
1993 ◽  
Vol 1993 (11) ◽  
pp. 1077-1079 ◽  
Author(s):  
George A. Olah ◽  
Qi Wang ◽  
Graham Sandford ◽  
Alexandros B. Oxyzoglou ◽  
G. K. Surya Prakash

1981 ◽  
Vol 46 (1) ◽  
pp. 286-299 ◽  
Author(s):  
František Brtník ◽  
Milan Krojidlo ◽  
Tomislav Barth ◽  
Karel Jošt

Preparation of oxytocin, arginine-vasopressin and its deamino-analogue serves as an example of use of 2,4,6-trimethylbenzyl group for protection of the cysteine sulfur atom in the peptide synthesis. This modified benzyl group is sufficiently stable under conditions of solvolytic removal of common amino-protecting groups and it can be cleaved off under mild conditions with liquid hydrogen fluoride or trifluoromethanesulfonic acid.


1980 ◽  
Vol 58 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Choi Chuck Lee ◽  
Eric C. F. Ko

When cyclobutane (1) is shaken at 0 °C with [3H]CF3SO3H (2-t) or with (2H)CF3SO3H (2-d), incorporation of T or D into the hydrocarbon layer readily occurred. All eight H atoms of 1 can be involved in the exchange since polydeuterated species including octadeuterated hydrocarbons were observed by mass spectrometry. In an experiment with 1 and 2-t, quenching of the acid layer with H2O gave a mixture of cyclobutanol, cyclopropylcarbinol, and allylcarbinol in the ratio of 61:37:2, respectively, as estimated by isotopic dilution, while vpc analysis of the hydrocarbon layer showed the presence of 1, methylcyclopropane, and 1-butene in the ratio of 66:30:4. The results are explained by a carbocationic chain mechanism, involving the formation of equilibrating bicyclobutonium ions. Similar but slower incorporation of T into the hydrocarbon layer was observed when 1 was treated with [3H]H2SO4.


2010 ◽  
Vol 65 (11) ◽  
pp. 1293-s1308 ◽  
Author(s):  
Laurent Plasseraud ◽  
Hélène Cattey ◽  
Philippe Richard

A new and facile synthetic route to the known neutral cluster ((PhCH2)2SnO)6[((PhCH2)2SnOH)2- (CO3)]2 (2) as well as its reactivity toward trifluoromethanesulfonic acid (HO3SCF3, TfOH) are reported. The solid-state structure of the new solvate 2·6C7H8 has been determined by single-crystal X-ray diffraction. The core of 2 can be described as a pair of coplanar pentanuclear [(PhCH2)2SnO]5 ladders bridged at their ends by two carbonate groups. Successive additions of TfOH to a suspension of 2 in CD3CN were monitored by 119Sn{1H} NMR spectroscopy showing the transformation of the fingerprint of 2 (δ = −244, −246, −306 ppm), via new upfield signals, to a final broad resonance located at δ = −474 ppm. Thereafter, two unprecedented ionic monobenzyltin(IV) oxo clusters, 3 and 4, resulting from a debenzylation reaction and exhibiting unusual hexa- and undecanuclear frameworks, respectively, have been isolated as single crystals.


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