Facile Synthesis of Some New Peptidomimetic <i>β</i><sup>3</sup>‐and <i>β</i><sup>2,3</sup>‐Amino Alcohols Possessing Pyridyl Moiety via Reductive Ring Opening of Pyridyl‐isoxazolidines
作者:Gagandeep Singh、Naman Gupta、Nidhi Sethi、Vivek Gupta、Tilak Raj、Mohan Paul Singh Ishar
DOI:10.1002/cbdv.202301323
日期:2024.2
Regio- and stereoselective 1,3-dipolar cycloadditions of C-(3-pyridyl)-N-phenylnitrone (2) with variedly substituted dipolarophiles (3, 4) were carried out to obtain substituted pyridyl-isoxazolidines (5–8). Reductive cleavage of pyridyl-isoxazolidines (5–8) with ammonium formate, methanol−THF solvents, at ambient temperature, in the presence of Pd/C provided a facile route for the synthesis of β3-and
C -(3-吡啶基) -N-苯基硝酮 ( 2 ) 与不同取代的亲偶极试剂 ( 3, 4 ) 进行区域和立体选择性 1,3-偶极环加成反应,得到取代的吡啶基异恶唑烷 ( 5 – 8 )。在环境温度下,在 Pd/C 存在下,用甲酸铵、甲醇-THF 溶剂还原吡啶基异恶唑烷 ( 5 – 8 ),为合成β 3 - 和β 2,3 - 氨基醇提供了一条简便的途径( 9 – 12 ),替换模式对扭转角有显着影响。获得的化合物( 9-12 )是有价值的支架,可用于肽模拟物。因此,本发明的异恶唑烷环的还原开环方法避免了使用昂贵设备的缺点以及使用氢气所涉及的危险。在双环异恶唑烷 ( 8a – c ) 的情况下优先形成氨基醇,这阻止了任何再环化,这通过 DFT 计算合理化。