Regioselective ortho-alkylation of N,N-diethylbenzamides via lithiation and copper transmetalation
作者:Dario Pini、Stefano Superchi、Piero Salvadori
DOI:10.1016/0022-328x(93)83206-b
日期:1993.6
One-pot ortho-lithiation and copper transmetalation with CuCN.LiCl of N,N-diethylbenzamides afford the corresponding aryl cyanocuprate, which gives coupling with some aliphatic halides in fair to good yields.
Formal Synthesis of Angiogenesis Inhibitor NM-3
作者:William E. Bauta、Dennis P. Lovett、William R. Cantrell、Brian D. Burke
DOI:10.1021/jo034165c
日期:2003.7.1
We report the formal synthesis of angiogenesis inhibitor NM-3 (1) in six steps from either of the 2,4-dimethoxyhalobenzenes 13a,b or 3,5-dimethoxychlorobenzene (13c). The first key reaction is the regiospecific alkylation/rearrangement between the aryne derived from 13a-c with sodium diethylmalonate in THF to produce diester 11, which after hydrolysis and cyclization affords homophthalic anhydride 3. The second is the reaction of anhydride 3 with either ethyl 2-methylmalonate (28a), in the presence of 1,1'-carbonyldiimidazole, or ethyl-2-methylmalonyl chloride (28b) under basic conditions to afford key isocoumarin 27. The conversion of 27 constitutes a formal synthesis of NM-3.
Anomalous Face-Selectivity in Sharpless Asymmetric Dihydroxylation of <i>o</i>-Allylbenzamides