155872-00-7Relevant articles and documents
Efficient semihydrogenation of the C-C triple bond using palladium on pumice as catalyst
Gruttadauria, Michelangelo,Noto, Renato,Deganello, Giulio,Liotta, Leonarda F.
, p. 2857 - 2858 (1999)
An efficient semihydrogenation of C-C triple bonds was achieved using palladium on pumice as the catalyst with a metal loading of 3% wt. The results obtained showed better selectivity when compared with Pd/C and better activity when compared with Lindlar'
Further improvements of the dibutyl tin oxide-catalyzed regioselective diol tosylation
Guillaume, Michel,Lang, Yolande
experimental part, p. 579 - 582 (2010/04/02)
In this Letter, we report that selective monotosylation of a 1,2-diol is possible using only 0.1 mol % of Bu2SnO. More interestingly, we found that the corresponding tin acetal 3b gave faster conversions and more reproducible reaction times. Moreover, the loading of this catalyst could be as low as 0.05-0.005 mol %.
SYNTHESIS OF SOME 2'-C-ALKYL DERIVATIVES OF 9-(2-PHOSPHONOMETHOXYETHYL)ADENINE AND RELATED COMPOUNDS
Cvorakova, Hana,Holy, Antonin,Rosenberg, Ivan
, p. 2069 - 2094 (2007/10/02)
To study the effect of β-substitution in 2'-alkyl derivatives of 9-(2-phosphonomethoxyethyl)adenine (Ia) on the antiviral activity or group specificity, these derivatives were synthesized. 9-(2-Hydroxyalkyl)adenines VIII were prepared by alkylation of adenine with suitably substituted oxiranes XIII or 2-hydroxyalkyl p-toluenesulfonates IV and VI.After protection of the adenine amino group by benzylation (compounds IX) or amidine formation (compounds X), the intermediates were alkylated with bis(2-propyl) p-toluenesulfonyloxymethanephosphonate (XI) in the presence of sodium hydride.After deprotection, the obtained phosphonate diesters XII were converted into phosphoniuc acids I by transsilylation and hydrolysis.This synthetic scheme was used for the preparation of ethyl (Ie), propyl (If), 2-propyl (Ig), 2-methylpropyl (Ih), cyclopropyl (Ii), cyclohexyl (Ij), benzyl (Ik) and phenyl (Il) derivatives.The 2'-trifluoromethyl derivative XXIIa was prepared analogously from 9-(2-hydroxy-3,3,3-trifluoropropyl)adenine (XXa), obtained by alkylation of adenine sodium salt with 2-hydroxy-3,3,3-trifluoropropyl bromide. 2,6-Diaminopurine derivative XXIIb was obtained analogously. 2'-Trimethylsilyl derivative XIXa was obtained by alkylation of adenine with 2-phosphonylmethoxy-3-(4-toluenesulfonyloxy)propyltrimethylsilane (XVII) followed by transsilylation and hydrolysis of diester XVIIIa. 9-(3-Phosphonomethoxybutyl)adenine (XXVIII) and 9-(2-methyl-2-phosphonomethoxypropyl)adenine (XXXV) were prepared from the corresponding hydroxy derivatives XXVIb and XXXII, respectively, by the same reaction pathway as derivatives I.
