Regioselective Bipyrrole Coupling of Pyrroles and 3-Substituted Pyrroles Using Phenyliodine(III) Bis(trifluoroacetate)
作者:Yasuyuki Kita、Toshifumi Dohi、Koji Morimoto、Motoki Ito
DOI:10.1055/s-2007-983798
日期:2007.9
A series of electron-rich bipyrroles were prepared by the regioselective, phenyliodine(III) bis(trifluoroacetate) (PIFA) induced oxidative coupling of pyrroles in the presence of bromotrimethylsilane. Using pyrrole and 3,4-disubstituted pyrroles gave exclusively 2,2′-linked bipyrroles without the formation of other bipyrrole regioisomers. The 3-alkyl- or 3-aryl-substituted pyrroles gave unsymmetrical
A facile three‐step synthesis of 2‐(2‐aminophenyl)pyrrole (1) and 2‐[(2‐aminomethyl)phenyl]pyrrole (2) is reported by use of Suzuki coupling of N‐Boc‐pyrrol‐2‐yl boronic acid (3) and o‐substituted aryl halogenides, followed by hydrogenation. The Pd‐catalyzed cross‐coupling reaction is optimized to be applicable to a wide range of substitued aryl halogenides, with electron‐donating and electron‐withdrawing
据报道,通过N -Boc-吡咯-2-基的Suzuki偶联,可以轻松实现三步合成2-(2-氨基苯基)吡咯(1)和2-[((2-氨基甲基)苯基]吡咯(2)。硼酸(3)和邻位取代的芳基卤化物,然后氢化。对Pd催化的交叉偶联反应进行了优化,以适用于具有电子给体和吸电子取代基5a,5b,5c,5d,5e,5f,5g的广泛取代的芳基卤化物。此外,邻溴代苯胺和3的Pd催化偶联可用于吡咯并[1,2 - c ]喹唑啉-5(6 H)-一(8)的一步制备。J.杂环化学。(2011)。
<i>meso</i>-Dibenzoporphycene has a Large Bathochromic Shift and a Porphycene Framework with an Unusual<i>cis</i>Tautomeric Form
meso‐Monobenzoporphycene (mMBPc) and meso‐dibenzoporphycene (mDBPc), in which one or two benzene moieties are fused at ethylene‐bridged positions (meso‐positions) of porphycene, were prepared in an effort to further delocalize the π‐electrons within the porphycene molecule. mMBPc and mDBPc were fully characterized by mass spectrometry, 1H and 13C NMR spectroscopy, and X‐ray crystallography. The longest‐wavelength
制备了内消旋-单苯并卟啉(mMBPc)和内消旋-二苯并卟啉(mDBPc),其中一或两个苯部分在卟啉的乙烯桥连位置(内消旋位置)融合,以进一步使π电子在电子中的离域化卟啉分子。通过质谱,1 H和13 C NMR光谱以及X射线晶体学对mMBPc和mDBPc进行了全面表征。与未取代的卟啉(Pc)相比,mMBPc和mDBPc的最长波长Q波段分别红移了92 nm和418 nm。电化学测量表明,HOMO是不稳定的,而LUMO是由内消旋的稠合苯部分稳定的 职位。此外,尽管实际上所有已知的卟啉衍生物都采用反互变异构形式,但XPS和理论研究均支持mDBPc基态存在顺式互变异构形式。
Synthesis of Planar <i>meso</i>-Aryl Rosarins: A Reversible Antiaromatic/Aromatic Interconversion
Novel 24π antiaromatic and 26π aromatic meso-aryl rosarins were successfully obtained for the first time from β-free bipyrrole through a one-pot synthesis. Because of the absence of substituents at the β-positions of the pyrrole units, the β-free pristine rosarin backbones were highlyplanar, as confirmed using X-ray crystallography. Optical measurements indicated interconversion between 24π antiaromatic