Superelectrophiles in Synthesis: Preparation of Aromatic Imides
作者:Sean H. Kennedy、Mark N. Schaeff、Douglas A. Klumpp
DOI:10.1021/acs.joc.9b01437
日期:2019.11.1
Aromatic carboxylic acids are found to undergo reactions with isocyanates, wherein triflic acid promotes the formation of aromatic imide products in fair to good yields. It is proposed that the carboxylic acid group directs the isocyanate electrophile to the ortho-position. This is thought to occur by the formation of a temporary carbamic acid anhydride group, which cleaves upon ortho-functionalization
Iodine-catalyzed oxidative multiple C–H bond functionalization of isoquinolines with methylarenes: an efficient synthesis of isoquinoline-1,3,4(2H)-triones
作者:Di Zhu、Wen-Kun Luo、Luo Yang、Da-You Ma
DOI:10.1039/c7ob01539a
日期:——
An iodine-catalyzed multiple C-H bonds functionalization of isoquinolines with methylarenes via successively benzylic sp3 C-H iodination/N-benzylation/amidation/double sp2 C-H oxidation sequence is developed. This reaction utilizes un-functionalized isoquinolines and readily available methylarenes as starting materials, proceeds under metal-free conditions, and avoids muti-step experimental operation
Ruthenium tetroxide oxidation of 3,4-dihydroisoquinolin-1(2H)-ones: An efficient synthesis of isoquinoline-1,3,4(2H)-triones.
作者:Shigeyuki YOSHIFUJI、Yukimi ARAKAWA
DOI:10.1248/cpb.37.3380
日期:——
Ruthenium tetroxide (RuO4) oxidation of 3, 4-dihydroisoquinolin-1(2H)-ones produced the corresponding isoquinoline-1, 3, 4(2H)-triones in good yields. In the cases of N-alkyl derivatives having two oxidation sites adjacent to the nitrogen atom, regioselective endocyclic oxidation was observed.
A highly enantioselectiveaza-Friedel–Craftsreaction of structurally new ketimines with indoles and pyrrole is developed by using a chiral phosphoric acid as the catalyst. This protocol enables the first enantioselective synthesis of isoquinoline-1,3(2H,4H)-dione derivatives in good to excellent yields (up to 99% yield) and excellent enantioselectivities (up to >99% ee).
view of these observations, an unusual [4+2] cycloaddition of the electron-rich enol 21 with singletoxygen is proposed to be responsible for the formation of products 7 and 16, while products 6, 14 and 15 arise from both the [4+2] cycloaddition and the usual Schenck ene reaction pathways. This special diene reactivity of the isoquinolinone system towards singletoxygen is further interpreted by frontier