Stereochemical Study on 1,3-Dipolar Cycloaddition Reactions of Heteroaromatic<i>N</i>-Ylides with Symmetrically Substituted cis and trans Olefins
作者:Otohiko Tsuge、Shuji Kanemasa、Shigeori Takenaka
DOI:10.1246/bcsj.58.3137
日期:1985.11
Stereochemistry of the cycloadditions of twenty-four heteroaromatic N-ylides with several symmetrically substituted cis and trans olefins has been investigated. Cyclic and acyclic cis olefins cycloadd to the and form of the ylides in a highly endo-selective manner giving almost quantitative yields of stereospecific endo 3+2 cycloadducts. N-Ylides stabilized with a substituent of carbonyl type react
A convenient synthesis of polyfluoroalkyl-substituted pyrazolo[1,5-a] pyridine, pyrrolo[1,2-b]pyridazine and indolizine derivatives
作者:Xue-chun Zhang、Wei-yuan Huang
DOI:10.1016/s0022-1139(97)00118-8
日期:1998.1
(1b) or N-amino-isoquinolinium iodide (1c), N-phenacylpyridazinium (4), N-phenacylpyridinium (6a–c), and N-phenacylisoquinolinium (6d) bromides in DMF to give poly(per)fluoroalkyl-substituted pyrazolo[1,5-a] pyridine (3), pyrrolo[l,2-a]pyridazine (5) and indolizine (7 and 8) derivatives, respectively.
Stereochemical Study on 1,3-Dipolar Cycloaddition Reactions of Heteroaromatic<i>N</i>-Ylides with Unsymmetrically Substituted Olefinic Dipolarophiles
作者:Otohiko Tsuge、Shuji Kanemasa、Shigeori Takenaka
DOI:10.1246/bcsj.58.3320
日期:1985.11
Regioselectivity and stereoselectivity of the cycloadditions of heteroaromatic N-ylides with unsymmetrically-substituted olefins such as methyl-substituted cis olefins, an acrylate, the related olefins, trans nitro olefins, and other trans olefins have been investigated. These cycloadditions are highly regioselective, while the stereoselectivity depends upon both the electronic and steric nature of
A One-Step Approach to 1-(Fluoroalkyl)indolizine Derivatives
作者:Xue-chun Zhang、Wei-yuan Huang
DOI:10.1055/s-1999-3675
日期:——
A facile one-step method is presented for the synthesis of 1-(fluoroalkyl)-substituted indolizine derivatives in moderate to good yields by reactions of pyridinium, 4-methylpyridinium, isoquinolinium, and pyridazinium ylides with 2-bromo-3,3,3-trifluoropropene and 1-iodo-2-(polyfluoroalkyl)ethenes, respectively, in the presence of base.