Divergent NHC-Catalyzed Oxidative Transformations of 3-Bromoenal: Selective Synthesis of 2<i>H</i>-Pyran-2-ones and Chiral Dihydropyranones
作者:Gang Wang、Xia Chen、Gaohan Miao、Weijun Yao、Cheng Ma
DOI:10.1021/jo400950j
日期:2013.6.21
A selectivesynthesis of either 2H-pyran-2-ones (4) or chiral dihydropyranones (6) from the same substrates of 3-bromoenals and 1,3-dicarbonyl compounds upon oxidative N-heterocyclic carbene catalysis is presented. It is shown that the oxidative transformation of 3-bromoenals under NHC catalyst can be well controlled to proceed through two pathways, i.e., elimination of reducible β-bromide or by an
Palladium-Catalyzed One-Pot Sonogashira Coupling,<i>exo</i>-<i>dig</i>Cyclization and Hydride Transfer Reaction: Synthesis of Pyridine-Substituted Pyrroles
作者:Kommuri Shekarrao、Partha Pratim Kaishap、Sanjib Gogoi、Romesh C. Boruah
DOI:10.1002/adsc.201401117
日期:2015.4.13
An efficient palladium(II)‐catalyzed method for the synthesis of alkylated pyridine‐substituted pyrroles has been developed by a one‐pot three component reaction of β‐bromovinyl aldehydes, primary amines and 2‐alkynylpyridines in good yields. The reactions can also provide an efficient route to 2‐picolinoylpyrroles by slightly altering the reaction conditions.
Cascade imination, Buchwald–Hartwig cross coupling and cycloaddition reaction: synthesis of pyrido[2,3-d]pyrimidines
作者:Pallabi Saikia、Gitarthi Sharma、Sanjib Gogoi、Romesh C. Boruah
DOI:10.1039/c5ra00725a
日期:——
A novel and efficient palladium catalyzed method was developed for the synthesis of wide range of pyrido[2,3-d]pyrimidines, using readily available β-bromovinyl/aryl aldehydes and 6-amino-1,3-dialkyluracils as the starting materials with good yields. This reaction proceeds via cascade imination/Buchwald–Hartwig cross coupling/cycloaddition reactions undermicrowaveirradiation and solvent free conditions
开发了一种新颖高效的钯催化方法,以易得的β-溴乙烯基/芳基醛和6-氨基-1,3-二烷基尿嘧啶为原料,合成了广泛的吡啶并[2,3- d ]嘧啶。良品率高。该反应通过微波辐射和无溶剂条件下的级联亚胺/ Buchwald-Hartwig交叉偶联/环加成反应进行。
Enantioselective Synthesis of Spiro[indoline-3,2′-pyrroles] through N-Heterocyclic-Carbene-Catalyzed Formal [3+2] Annulation
An N-heterocyclic-carbene-catalyzed asymmetric formal [3+2] annulation reaction of isatin N-Boc ketimines (Boc = tert-butyloxycarbonyl) and 3-bromoenals was developed for the construction of spiro[indoline-3,2′-pyrrole] derivatives with one quaternary chiral center in good yields (up to 81 % yield) with excellent enantioselectivity (up to 99 % ee).
Construction of [2,5]-Furanophanes by Carbene-Mediated Alkynyl Migration Cyclization
作者:Qiu Shi、Yang Chen、Tongxiang Cao、Shifa Zhu
DOI:10.1021/acs.orglett.2c03185
日期:2022.11.11
Heterophanes are widely found in natural products and drug molecules. Herein, an efficient method for the construction of [2,5]-furanophanes with differentring types and ringsizes was developed. This method is carried out with furan-free precursor throughintramolecular carbene-mediated alkynyl migration and tandem cyclization strategy. In addition, a series of tetrafuran structures can be obtained by oxidative