89985-91-1Relevant articles and documents
Catalytic Transformations of 2-Pyridones by Rhodium-Mediated Carbene Transfer
Li, Qiongya,Shao, Ying,Su, Jiahui,Sun, Jiangtao
supporting information, p. 1637 - 1641 (2022/03/14)
An enantioselective cyclopropanation reaction of N-substituted 2-pyridones with diazo compounds has been realized by using a chiral rhodium complex as the catalyst, and the corresponding chiral cyclopropanes could be formed in good yields with high enantioselectivities. Moreover, using acceptor-acceptor dimethyl 2-diazomalonate as the carbene precursor, a novel 1,4-rearrangement of a Boc group from N to C has also been discovered under rhodium catalysis.
Kinetics and reaction mechanism of aminolyses of benzyl 2-pyridyl carbonate and t-butyl 2-pyridyl carbonate in acetonitrile
Bae, Ae Ri,Um, Ik-Hwan
body text, p. 1547 - 1550 (2012/07/28)
Second-order rate constants (kN) have been measured spectrophotometrically for the reactions of benzyl 2- pyridyl carbonate 3 and t-butyl 2-pyridyl carbonate 4 with a series of alicyclic secondary amines in MeCN at 25.0 ± 0.1 ° C. Substrate 4 is much less reactive than 3 and the steric hindrance exerted by the bulky t-Bu group in 4 has been attributed to its decreased reactivity. The Bronsted-type plots for the reactions of 3 and 4 are linear with ssnuc = 0.57 and 0.45, respectively. Thus, the reactions have been concluded to proceed through a concerted mechanism, although the current reactions were expected to proceed through a stepwise mechanism with a zwitterionic tetrahedral intermediate T±. It has been proposed that the rate of leaving-group expulsion is accelerated by the intramolecular H-bonding interaction in T± and the "push" provided by the RO group through the resonance interaction. Thus, the enhanced nucleofugality forces the reactions to proceed through a concerted mechanism. The reactivity-selectivity principle (RSP) is not applicable to the current reaction systems, since the reaction of the less reactive 4 results in a smaller ssnuc than that of the more reactive 3. Steric hindrance exerted by the bulky t-Bu group in 4 has been suggested to be responsible for the failure of the RSP. Copyright
New Amino-protective Reagents for t-Butoxycarbonylation and Benzyloxycarbonylation of Amines and Amino Acids
Kim, Sunggak,Lee, Jae In,Yi, Kyu Yang
, p. 3570 - 3575 (2007/10/02)
New amino-protective reagents for t-butoxycarbonylation and benzyloxycarbonylation of amines and amino acids have been developed. t-Butyl 2-pyridyl carbonate and t-butyl S-(2-pyridyl) thiocarbonate react cleanly with various amines and amino acids to afford N-Boc amines and N-Boc amino acids in high yields.Benzyl 2-pyridyl carbonate and O-benzyl S-(2-pyridyl) thiocarbonate are also found to be very effective in the benzyloxycarbonylation of amino acids.