Synthesis of 2,3-Dihydropyrrolizines from Weinreb 3-(Pyrrolidin-2-ylidene)propionamides or Weinreb<i>N-</i>Vinylprolinamides
作者:Alfonso González-Ortega、Luis Calvo、M. Carmen Sañudo
DOI:10.1055/s-2002-35220
日期:——
Weinreb 3-(pyrrolidin-2-ylidene)propionamides and Weinreb N-vinylprolinamides were used for the synthesis of 2,3-dihydropyrrolizines. The selective reaction of the carboxamide group with organometallic compounds allowed us to obtain a great variety of carbonyl intermediates, analogous to the Hantzsch and Knorr pyrrole synthesis, which were thermally cyclized.
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-Mediated C(<i>sp</i>
<sup>2</sup>
)-C(<i>sp</i>
<sup>3</sup>
) Cross-Dehydrogenative Coupling Reaction: α-Alkylation of Push-Pull Enamines and α-Oxo Ketene Dithioacetals
作者:Dongping Cheng、Lijun Wu、Zhiteng Deng、Xiaoliang Xu、Jizhong Yan
DOI:10.1002/adsc.201700853
日期:2017.12.19
A novel, metal‐free cross‐dehydrogenativecoupling (CDC) reaction of C(sp2)–H bonds of enamines and α‐oxo ketene dithioacetals with C(sp3)–H bonds of 1,3‐diarylpropenes mediated by 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) is reported. The α‐alkylation products are obtained with moderate to good yields. The method provides an efficient and alternative strategy for the synthesis of the corresponding
Influence of substituents on regioselectivity of vinyllithium formation with acrylic acid Derivatives
作者:Richard R Schmidt、Heike Speer
DOI:10.1016/s0040-4039(01)82926-9
日期:1981.1
β-Alkoxy, β-dialkylamino, and β-N-alkylacylamino substituents determine the regioselectivity of the vinylic deprotonation of acrylic ester and nitrile derivatives: either α- or β-vinyllithium species may be generated. The corresponding acrylamides or systems with additional α-alkyl or α-methylmercapto substituents are lithiated at β-position.
Copper‐Mediated Synthesis of (
<i>E</i>
)‐
<i>β</i>
‐Aminoacrylonitriles from 1,2,3‐Triazine and Secondary Amines
作者:Cheng‐Hsin Ou Yang、Wan‐Hsuan Liu、Sheng Yang、Yao‐Yu Chiang、Jiun‐Jie Shie
DOI:10.1002/ejoc.202200209
日期:2022.3.29
An efficient approach for the stereoselective synthesis of (E)-β-aminoacrylonitriles from 1,2,3-triazine is presented. The reactions employ Cu(OAc)2 to promote direct 1,2,3-triazine coupling with various secondary amines and subsequent aerobic oxidation without the participation of ligand, base or chemical oxidant additives. This user-friendly protocol has merits of substrate availability, easy operation
提出了一种从 1,2,3-三嗪立体选择性合成 ( E ) -β-氨基丙烯腈的有效方法。该反应使用 Cu(OAc) 2来促进 1,2,3-三嗪与各种仲胺的直接偶联和随后的有氧氧化,而无需配体、碱或化学氧化剂添加剂的参与。这种用户友好的协议具有底物可用性、操作简单和产品产率高的优点,具有优异的 ( E )- 立体选择性。