Facile Preparation of Various Heteroaromatic Compounds via Azatitanacyclopentadiene Intermediates
作者:Daisuke Suzuki、Youhei Nobe、Yuko Watai、Ryoichi Tanaka、Yuuki Takayama、Fumie Sato、Hirokazu Urabe
DOI:10.1021/ja0502730
日期:2005.5.25
in a highly regioselective manner. Their subsequent reaction with sulfonylacetylene afforded pyridyltitanium compounds, which, upon reaction with electrophiles, gave substituted pyridines virtually as a single isomer. When optically active nitriles were used in this reaction, chiral pyridines were obtained without loss of the enantiopurity. Alternatively, the azatitanacyclopentadiene prepared from an
乙炔、腈和钛试剂 Ti(Oi-Pr)(4)/2 i-PrMgCl 的偶联以高度区域选择性的方式生成了新的氮杂钛烷环戊二烯。它们随后与磺酰乙炔反应得到吡啶基钛化合物,在与亲电子试剂反应时,得到取代的吡啶,实际上是单一异构体。当在该反应中使用旋光腈时,可以在不损失对映体纯度的情况下获得手性吡啶。或者,由不对称乙炔制备的氮杂钛烷环戊二烯与醛或另一种腈反应,再次以区域选择性方式得到具有四个不同取代基的呋喃或吡咯。