Directed <i>ortho</i>-metalation–nucleophilic acyl substitution strategies in deep eutectic solvents: the organolithium base dictates the chemoselectivity
作者:Simone Ghinato、Giuseppe Dilauro、Filippo Maria Perna、Vito Capriati、Marco Blangetti、Cristina Prandi
DOI:10.1039/c9cc03927a
日期:——
Directed ortho metalation (DoM) or nucleophilic acylsubstitution (SNAc) can be efficiently programmed on the same aromatic carboxylic acid amide, in a choline chloride-based eutectic mixture, by simply switching the nature of the organolithium reagent. Telescoped, one-pot ortho-lithiation/Suzuki–Miyaura cross-couplings have also been demonstrated for the first time in Deep Eutectic Solvents.
定向邻位金属化(d Ò M)或亲核酰基取代(S Ñ AC)可以有效地设定为在同芳族羧酸酰胺,在基于氯化物胆碱共熔混合物,通过简单地切换有机锂试剂的性质。伸缩式单罐正锂化/铃木-宫浦交叉联结也已在深共晶溶剂中首次得到证明。
Directed lithiations: the effect of varying directing group orientation on competitive efficiencies for a series of tertiary amide, secondary amide, and alkoxide directed ortho lithiations
作者:Peter Beak、Shawn T. Kerrick、Donald J. Gallagher
DOI:10.1021/ja00076a022
日期:1993.11.1
Significant differences for competitive efficiencies in directed ortho lithiations for single functional groups in three series, the secondary benzamides 1-4, the tertiary benzamides 5-11, and the benzylic alcohols 12-17, are reported. For both amide series the efficiencies increase as the oxygen and ortho hydrogen in the substrate are more coplanar with the aromatic ring; however, for the alcohol
Direct <i>ortho</i> Cupration: A New Route to Regioselectively Functionalized Aromatics
作者:Shinya Usui、Yuichi Hashimoto、James V. Morey、Andrew E. H. Wheatley、Masanobu Uchiyama
DOI:10.1021/ja074669i
日期:2007.12.1
electrophilic functional groups, such as cyano, amide, and halogens. Direct cupration, followed by electrophilic trapping, provided a convenient preparative method for 1,2- or 1,2,3-multisubstituted aromatic compounds. The functionalized aromatic cuprate intermediates were also found to undergo oxidation reactions very efficiently and with high regio- and chemoselectivity to afford functionalized phenol,
Complex induced proximity effect enhancement in α-silyl carbanion generation. A general conversion of 2-silyl benzamides into 2-fluorosilylacetophenones
作者:Paul A. Brough、Stephen Fisher、Baoping Zhao、Ryan C. Thomas、Victor Snieckus
DOI:10.1016/0040-4039(96)00446-7
日期:1996.4
LDA treatment of 2-silylated benzamides 1 affords 2-fluorosilylated acetophenones 3 in a general process likely driven by CIPE-facilitated α-silylcarbanion formation and rearrangement (Scheme 3); oxidation (H2O2) of the products gives 2-hydroxyacetophenones and catechols (Scheme 4).
LDA处理2-甲硅烷基化的苯甲酰胺1在一般过程中可能由CIPE促进的α-甲硅烷基碳负离子的形成和重排驱动生成2-氟甲硅烷基化的苯乙酮3 (方案3);产物的氧化(H 2 O 2)得到2-羟基苯乙酮和儿茶酚(方案4)。
Chemoselective Reduction of Sterically Demanding <i>N</i>,<i>N</i>-Diisopropylamides to Aldehydes
作者:Peihong Xiao、Zhixing Tang、Kai Wang、Hua Chen、Qianyou Guo、Yang Chu、Lu Gao、Zhenlei Song
DOI:10.1021/acs.joc.7b02868
日期:2018.2.16
EtOTf and LiAlH(OEt)3 in the absence of base were found to be optimal for reducing extremely sterically demanding 2,6-disubstituted N,N-diisopropylbenzamides. The reaction tolerates various reducible functional groups, including aldehyde and ketone. 1H NMR studies confirmed the formation of imidates stable in water. The synthetic usefulness of this methodology was demonstrated with N,N-diisopropylamide-directed