Scope and Mechanism of Direct Indole and Pyrrole Couplings Adjacent to Carbonyl Compounds: Total Synthesis of Acremoauxin A and Oxazinin 3
作者:Jeremy M. Richter、Brandon W. Whitefield、Thomas J. Maimone、David W. Lin、M. Pilar Castroviejo、Phil S. Baran
DOI:10.1021/ja074392m
日期:2007.10.1
Full details are provided for a recently invented method to couple indoles and pyrroles to carbonyl compounds. The reaction is ideally suited for structurally complex substrates and exhibits high levels of chemoselectivity (functional group tolerability), regioselectivity (coupling occurs exclusively at C-3 of indole or C-2 of pyrrole), stereoselectivity (substrate control), and practicality (amenable
提供了最近发明的将吲哚和吡咯与羰基化合物偶联的方法的全部细节。该反应非常适合结构复杂的底物,并表现出高水平的化学选择性(官能团耐受性)、区域选择性(偶联仅发生在吲哚的 C-3 或吡咯的 C-2)、立体选择性(底物控制)和实用性(适合)以扩大规模)。此外,四元立构中心很容易且可预测地生成。该反应已应用于许多合成问题,包括天然产物 hapalindole 家族成员、酮咯酸、acremoauxin A 和恶嗪宁 3 的全合成。从机理上讲,该偶联方案似乎通过需要生成的单一电子转移过程来操作与羰基相邻的缺电子自由基,然后被吲哚或吡咯阴离子拦截。
Alkylation process
申请人:Canadian Patents & Development Limited
公开号:US04070366A1
公开(公告)日:1978-01-24
Substituted pyrrole compounds, such as 3-ethyl-4-methyl-5-carbethoxy pyrrole, 2,4-dimethyl-3-acetyl pyrrole and 2-methyl-5-carboxy pyrrole-4-propionic acid diethyl ester, are alkylated in a single step by reaction with an aldehyde or ketone in the presence of both an acid condensing agent such as hydriodic acid and a compatible reducing agent such as metallic zinc or stannous chloride. Suitable carbonyl reactants include formaldehyde, paraldehyde, isobutyraldehyde, acetone, cyclohexanone and methyl-isobutyl ketone. This application is a continuation application of U.S. application Ser. No. 281,624 filed Aug. 18, 1972, now abandoned, which is a continuation-in-part application of U.S. application Ser. No. 832,001, filed June 10, 1969, now abandoned.
Pyrrole and alkyl pyrroles react spontaneously with phenyl isothiocyanate to produce C-substituted derivatives. The structures of the products are confirmed by physical methods. The reaction is cat...
吡咯和烷基吡咯与异硫氰酸苯酯自发反应生成 C 取代的衍生物。产品的结构通过物理方法确认。反应是猫...
Chiral spiro phosphoric acid-catalysed enantioselective reaction of ketenes with N–H pyrroles
作者:Qian-Yi Wang、Teng-Fei Liu、Li-Feng Chu、Yun Yao、Chong-Dao Lu
DOI:10.1039/d1cc05307h
日期:——
In the presence of a chiral spiro phosphoric acid catalyst, the asymmetric reaction of disubstituted ketenes with N–H pyrroles occurred to afford enantioenriched C-acylated pyrroles bearing α-stereogenic carbon centres. The described reaction constitutes a rare example of a catalytic asymmetric reaction of ketenes with carbon-based nucleophiles.
Synthesis of 2,3-Disubstituted Pyrroles and Pyridines from 3-Halo-1-azaallylic Anions
作者:Wim Aelterman、Norbert De Kimpe、Vladimir Tyvorskii、Oleg Kulinkovich
DOI:10.1021/jo000724t
日期:2001.1.1
A new synthesis of 2,3-disubstituted pyrroles and pyridines is described. The reaction of 3-halo-1-azaallylic carbanions, regiospecifically generated from alpha-halogenated ketimines, with omega-iodoazides led to the regiospecific formation of omega-azido-alpha-haloketimines. Treatment of these functionalized imines with tin(II) chloride afforded halogenated five- and six-membered cyclic imines, which