Substrate Controlled Regioselective Bromination of Acylated Pyrroles Using Tetrabutylammonium Tribromide (TBABr<sub>3</sub>)
作者:Shuang Gao、Travis K. Bethel、Tayeb Kakeshpour、Grace E. Hubbell、James E. Jackson、Jetze J. Tepe
DOI:10.1021/acs.joc.8b01251
日期:2018.8.17
Electrophilic bromination of pyrroles bearing carbonyl substituents at C-2 typically results in a mixture of the 4- and 5-brominated species, generally favoring the 4-position. Herein, we describe a substrate-controlled regioselective bromination in which tetra-butyl ammonium tribromide (TBABr3) reacts with pyrrole-2-carboxamide substrates to yield the 5-brominated species as the predominant (up to
Iron and Manganese Complexes of 2-Carbonyl Pyrrolyls: Scorpionate Sandwich Anions and Extended Structures
作者:Lihong Li、Guy J. Clarkson、Martin R. Lees、Suzanne E. Howson、Sze-yin Tan、Scott S. Turner、Peter Scott
DOI:10.1021/om501218a
日期:2015.6.8
Attempts to synthesize complexes of Fe and Mn(II) with 2-amidopyrrolyl ligands (N–O) were unsuccessful, and only small amounts of the trivalent tris complexes M(N–O)3 were detected, although unusually in the case of Fe(III) a fac structure is observed. In contrast the 2-benzoylpyrrolyl systems give M(II) complexes, and in all instances thus far where Na+ is present, a scorpionate fac-[MII(N–O)3]− unit
尝试合成具有2-酰胺基吡咯烷配体(N–O)的Fe和Mn(II)的配合物,并且仅检测到少量的三价tris配合物M(N–O)3,尽管在Fe情况下不常见(III)观察到fac结构。相反,2-苯甲酰基吡咯基系统生成M(II)配合物,并且在迄今为止存在Na +的所有情况下,蝎子的fac- [M II(N–O)3 ] -单元自组装成三明治阴离子[M II(N–O)3 Na(O–N)3 M II ] -其中中心金属通过芳基单元的互指而有效地包封。通过使用2-(4-吡啶基)吡咯基酰胺配体容易地制备延伸结构。当使用Li +时,蝎形配体不组装,而是[M(N–O)2 ]单元提供菱形2D网格。Fe系统显示120 K时的自旋交叉。
Divergent synthesis of pyrrole carboxamides from pyrrole carboxaldehyde and formamides/amines <i>via</i> oxidative amidation involving pyrrole acyl radicals
作者:Joydev K. Laha、Surabhi Panday、J. Patrick Weber、Martin Breugst
DOI:10.1039/d3cc02766j
日期:——
A non-traditional approach for the synthesis of pyrrole carboxamides frompyrrole carboxaldehyde and formamides or amines with catalytic amounts of nBu4NI and TBHP as oxidants is reported herein. The method is operationally simple providing straightforward access to primary, secondary, and tertiary pyrrole carboxamides in good to excellent yields utilizing inexpensive reagents under mild conditions
本文报道了一种由吡咯甲醛和甲酰胺或胺以催化量的n Bu 4 NI和TBHP作为氧化剂合成吡咯甲酰胺的非传统方法。该方法操作简单,可在温和条件下利用廉价试剂以良好至优异的产率直接获得伯、仲和叔吡咯甲酰胺。与涉及离子反应的传统酰胺化不同,我们当前方法的机理研究揭示了 2- 或 3-吡咯酰基自由基的参与,否则很少假设。本方法的适用性在类药物化合物,即光学纯的碳依托咪酯酰胺的合成中得到进一步证明。
Birch Reduction of Electron-Deficient Pyrroles
作者:Timothy J. Donohoe、Paul M. Guyo
DOI:10.1021/jo961688u
日期:1996.1.1
BOATMAN R. J.; WHITLOCK H. W., J. ORG. CHEM. <JOCE-AH>, 1976, 41, NO 18, 3050-3051