Unambiguous Evidence for Efficient Chemical Catalysis of Adenosine Ester Aminolysis by Its 2‘/3‘-OH

Hierarchical approach to conformational search and selection of computational method in modeling the mechanism of ester ammonolysis

“…The results reported here can be related to an experimental study of the intramolecular aminolysis reactions in presence and absence of a vicinal OH group [57]. In agreement with the computational results for acceleration of the reaction via the hexagonal transition states, the lactamization of ornithinyl adenosine is orders of magnitude faster as compared to the lactamization of the corresponding deoxy compound.…”

Organocatalysis: Fundamentals and Comparisons to Metal and Enzyme Catalysis

“…Stabilization of the alkoxide moiety of the tetrahedral intermediate resulting from the addition H-Nu + RCOX can be realized by a neighbouring hydroxy group of the leaving group X. For instance, in aminolyses of adenosine 3 -ester derivatives are faster than aminolyses of the corresponding 3 -esters of 2 -deoxyadenosine [66]. This property is exploited by Nature in the ribosome (peptidyl t-RNA).…”

Successful Application of the Lipase as a Catalyst in the Combinative Approach, Using an Efficient and Selective Iterative Procedure for the Chemo-Enzymatic Alpha-Amino Group Protection in the Natural Amino Acids, Representing the Ornithyl Model System as a Starting Research Pattern: Homogeneous and Heterogeneous Synthesis

“…Also it is forwarded, that the synthesis of cyclic aliphatic, aromatic as well as aliphatic-aromatic esters (alcohol synthons) of the above noted protective groups (acyl synthons) as synthetic equivalents and the study of their reactive ability will be realized. [6,7,32], and the general and important role of A76 2'-OH in the ribose ring of peptidyl-tRNA for acceleration of peptidyl transferase reaction, during the protein biosynthesis on ribosome [33,34]. On the other hand the amino acid was used as its methyl ester, as well as it was used with its carboxyl free functional group, which determines the combinative approach, related to the selection of solvents media and lipase determination (free or immobilized).…”

“…In the presence of at least two functional groups in the amino acids, their selective protection is necessary and is required, with goal -to avoid (protect) the process from the unwanted side reactions, as well as the carrying out of the synthesis in the desired direction. Utilization of the 9-fluorenylmethyloxycarbonyl moiety (Fmoc) as a protecting group for the amino function of the amino acids in the solid-phase peptide synthesis [1] of the benzyloxycarbonyl protection (Z) -also as N-protective group -in the realization of the peptide synthesis in solution (solution-phase peptide synthesis) [2][3][4][5] as well as the permanent р-nitro benzoyl protecting group (Bz(NO 2 ) -for increasing of the sensitivity in the UV-area during the peptide analysis [3], and also for synthesis of model compounds [6,7], as well as for protection of nucleosides and nucleotides, and finally -for increasing of the sensitivity and selectivity in the nucleoside, nucleotide and oligonucleotide synthesis and analysis [8], enforce the using of protected biomonomer derivatives, and particularly in this case -of the protected amino acids. Fmoc-group is labile in basic media, but it is stable in acidic conditions, respectivelyit deprotects in the principle of the basic elimination (pyridine, or 10% diethylamine in DMF) [9].…”