Base-mediated 1,3-dipolar cycloaddition of pyridinium bromides with bromoallyl sulfones: a facile access to indolizine scaffolds
作者:Chetna Jadala、Velma Ganga Reddy、Namballa Hari Krishna、Nagula Shankaraiah、Ahmed Kamal
DOI:10.1039/d0ob01696a
日期:——
synthetic strategy has been developed for the construction of substituted indolizines from a unique combination of pyridiniumsalts and 2-bromoallyl sulfones. This approach does not compromise with the diverse substitutions on both the pyridiniumsalts and 2-bromoallyl sulfones. Wide substrate scope, operational simplicity, milder reaction conditions and good to moderate yields are the merits associated with
A metal-free approach for the synthesis of amides/esters with pyridinium salts of phenacyl bromides via oxidative C–C bond cleavage
作者:Kesari Lakshmi Manasa、Yellaiah Tangella、Namballa Hari Krishna、Mallika Alvala
DOI:10.3762/bjoc.15.182
日期:——
O-benzoylation of various amines/benzyl alcohols with pyridinium salts of phenacyl bromides is demonstrated to generate the corresponding amides and esters. This protocol facilitates the oxidative cleavage of a C–C bond followed by formation of a new C–N/C–O bond in the presence of K2CO3. Various pyridinium salts of phenacyl bromides can be readily transformed into a variety of amides and esters which is an
用苯甲酰溴的吡啶鎓盐对各种胺/苄醇进行N-和O-苯甲酰化的有效,简单和无金属的合成方法被证明可以生成相应的酰胺和酯。该方案有助于在存在K 2 CO 3的情况下促进C–C键的氧化裂解,然后形成新的C–N / C–O键。苯甲酰溴的各种吡啶鎓盐可以很容易地转化为各种酰胺和酯,这是有机合成中常规酰胺化和酯化的另一种方法。高官能团耐受性,广泛的底物范围和操作简便性是当前方案的突出优点。
Facile one-pot tandem synthesis of perfluoroalkylated indolizines under metal-free mild conditions
作者:Dong He、Yuhong Xu、Jing Han、Hongmei Deng、Min Shao、Jie Chen、Hui Zhang、Weiguo Cao
DOI:10.1016/j.tet.2017.01.005
日期:2017.2
A direct metal-free method for the synthesis of perfluoroalkylated indolizines by means of DIPEA-promoted tandem CN/CC bond formation was developed. Various substituted pyridines and bromoacetyl derivatives with methyl perfluoroalk-2-ynoates proceeded smoothly in this mild transformation, and the desired products were obtained in good to excellent yields under air.
开发了一种直接无金属的方法,该方法通过DIPEA促进的串联C N / C C键的形成来合成全氟烷基化的吲哚嗪。在这种温和的转化过程中,各种被全氟烷基-2-丙酮酸甲酯取代的吡啶和溴代乙酰基衍生物可顺利进行,并在空气中以良好或优异的收率获得所需的产物。
Reactions of ethyl cyanoformate with cycloimmonium salts: a direct pathway to fused or substituted azaheterocycles
作者:Cristina M. Al Matarneh、Mircea O. Apostu、Ionel I. Mangalagiu、Ramona Danac
DOI:10.1016/j.tet.2016.05.061
日期:2016.7
Aromatic cycloimmonium salts underwent different reaction pathways when treated with ethyl cyanoformate in triethyl amine medium, including selective γ-cyano substitutions (in case of phenanthrolinium and quinolinium salts) and 3+2 dipolar cycloadditions (for phthalazinium and isoquinolinium salts). When using phthalazinium salts, besides the 3+2 cycloaddition products (imidazo[2,1-a]phthalazines)
Silver-Promoted (4 + 1) Annulation of Isocyanoacetates with Alkylpyridinium Salts: Divergent Regioselective Synthesis of 1,2-Disubstituted Indolizines
作者:Yan Chen、Andrey Shatskiy、Jian-Quan Liu、Markus D. Kärkäs、Xiang-Shan Wang
DOI:10.1021/acs.orglett.1c02754
日期:2021.10.1
regioselective (4 + 1) annulation of isocyanoacetates with pyridinium salts is reported. The established protocol provides controlled, facile, and modular access to a range of synthetically useful N-fused heterocyclic scaffolds containing indolizines, pyrrolo[1,2-a]quinolines, pyrrolo[2,1-a]isoquinolines, and 1H-imidazo[4,5-a]indolizin-2(3H)-ones. A mechanistic pathway involving nucleophilic addition/protonati
报道了一种前所未有的银促进的区域选择性 (4 + 1) 异氰乙酸酯与吡啶盐的环化。已建立的协议提供对一系列合成有用的 N-稠合杂环支架的受控、简便和模块化访问,这些支架包含吲哚嗪、吡咯并 [1,2- a ] 喹啉、吡咯并 [2,1- a ] 异喹啉和 1 H -咪唑[4,5 - a ]indolizin-2(3 H )-ones。提出了涉及亲核加成/质子化/消除/环异构化的机制途径。