Synthesis and conformational analysis of chiral ureas incorporating<i>N</i>-1-phenylethyl groups. Manifestation of allylic 1,3-strain
作者:Marcos Hernández-Rodríguez、Roberto Melgar-Fernández、Eusebio Juaristi
DOI:10.1002/poc.939
日期:2005.8
The synthesis of novel chiral ureas (R,R)-2, (S,S)-3 and (R)-6 incorporating the α-phenylethyl group is described. Conformational analysis of these ureas, and of previously reported (R,R)-1, was carried out computationally, both at semiempirical (AM1 and PM3) and ab initio (HF and B3LYP) levels, and experimentally from x-ray crystallographic analysis of (R,R)-2 and (S,S)-3, and in the case of (R)-6
描述了结合有α-苯乙基的新型手性脲(R,R)-2,(S,S)-3和(R)-6的合成。这些尿素和先前报道的(R,R)-1的构象分析是在半经验水平(AM1和PM3)和从头算水平(HF和B3LYP)上进行的,并且是通过X射线晶体学分析从实验上进行的(R,R)-2和(S,S)-3,并且在(R)-6的情况下通过NOE NMR光谱测定。1.5-2.6千卡摩尔的相当偏好-1有利于与构象顺式C在-periplanar安排H键在α苯乙基ñ -取代和N C(O)段被发现,并且这种观察确认的相关性在该系统中的1,3烯丙基菌株。在氢键的可能性顺-periplanarÇ ħ...ö Ç Ñ安排被丢弃在(拓扑分析的光- [R ,- [R )- 1,在分子理论中的Bader原子框架内。版权所有©2005 John Wiley&Sons,Ltd.