Exploiting Hydrazones To Improve the Efficiency of 6π-Electrocyclization Reactions of 1-Azatrienes
作者:Matthew P. Ball-Jones、Jasper Tyler、Helena Mora-Radó、Werngard Czechtizky、María Méndez、Joseph P. A. Harrity
DOI:10.1021/acs.orglett.9b02455
日期:2019.9.6
The greater geometric lability of hydrazones compared to that of oximeethers is used as a basis to overcome the reluctance of Z-oxime ether azatrienes to undergo electrocyclization toward the synthesis of borylated (heteroaromatic) pyridines and ring-fused analogues. Such hydrazones now allow access to previously inaccessible tri- and tetrasubstituted 3-borylpyridines in high yields.
Rhodium(II)-Catalyzed and Thermally Induced Intramolecular Migration of<i>N</i>-Sulfonyl-1,2,3-triazoles: New Approaches to 1,2-Dihydroisoquinolines and 1-Indanones
作者:Run Sun、Yu Jiang、Xiang-Ying Tang、Min Shi
DOI:10.1002/chem.201504914
日期:2016.4.11
New rhodium(II)‐catalyzed or thermally induced intramolecular alkoxy group migration of N‐sulfonyl‐1,2,3‐triazoles has been developed, affording divergent synthesis of 1,2‐dihydroisoquinoline and 1‐indanone derivatives according to different conditions. N‐Sulfonyl keteneimine is the key intermediate for the synthesis of dihydroisoquinoline, whereas the aza‐vinyl carbene intermediate results in the
Palladium-Catalyzed Chemoselective Aminomethylative Cyclization and Aromatizing Allylic Amination: Access to Functionalized Naphthalenes
作者:Bangkui Yu、Houjian Yu、Hanmin Huang
DOI:10.1021/acs.orglett.0c03365
日期:2020.11.20
A palladium-catalyzedchemoselective aminomethylative cyclization and aromatizing allylic amination of enyne-tethered allylic alcohols with aminals is described. Under the reaction conditions, the cationic vinyl allylpalladium species undergoes selective migratory insertion of alkenes rather than reductive elimination with nucleophiles. This strategy provides an efficient and unique approach to the
De Novo Synthesis of Phenols and Naphthols through Oxidative Cycloaromatization of Dienynes
作者:Ming-Guang Rong、Tian-Zhu Qin、Xin-Rui Liu、Hong-Fa Wang、Weiwei Zi
DOI:10.1021/acs.orglett.8b02786
日期:2018.10.5
In this work, a rhodium-catalyzed oxidative cycloaromatization of dienynes, which provides a highly straightforward and efficient way to access polysubstituted naphthols and phenols under mild conditions, is described. Challenged electron-withdrawing groups are well tolerated in this protocol, and late-stage phenyl ring formation is demonstrated.