Regioselective Nucleophilic Addition of Organometallic Reagents to 3-Geminal Bis(silyl) <i>N</i>-Acyl Pyridinium
作者:Ya Wu、Linjie Li、Hongze Li、Lu Gao、Hengmu Xie、Zhigao Zhang、Zhishan Su、Changwei Hu、Zhenlei Song
DOI:10.1021/ol500302r
日期:2014.4.4
bis(silyl) N-acyl pyridinium has been described. Geminal bis(silane) shows contrasting roles that lead to different regioselectivities for the addition of different nucleophiles: its steric effect dominates to favor 1,6-addition of alkyl, vinyl, and aryl organometallicreagents; its directing effect dominates to favor 1,2-addition of less sterically demanding alkynyl Grignard reagents.
Lithiation of 2-Me3SiCHRC5H4N(R = H or SiMe3): influence of solvent on the nature of the product (from X-ray structure determinations) and asymmetric induction. A note on the lithiation of some analogous 3- and 4-methylpyridines
作者:Rocco I. Papasergio、Brian W. Skelton、Paul Twiss、Allan H. White、Colin L. Raston
DOI:10.1039/dt9900001161
日期:——
Metallation of 2-Me3SiCHRC5H4N (R = H or SiMe3) using LiBun in hexane, and in the presence of diethyl ether, and the ditertiary amines tmen (N,N,N′,N′-tetramethylethylenediamine) or sp [(–)sparteine] yields crystalline lithium complexes. These have been characterized using X-ray diffraction data for [Li2-C(SiMe3)2C5H4N}2-CH(SiMe3)2C5H4N}](1), [Li[2-C(SiMe3)2C5H4N]}2](2), [Li(tmen)2-C(SiMe3)2C5H4N}](3)
使用LiBu n在己烷中,在乙醚和二叔胺tmen(N,N,N ',N'-四甲基乙二胺)的存在下使用LiBu n对2-Me 3 SiCHRC 5 H 4 N(R = H或SiMe 3)进行金属化)或sp [(–)sparteine]产生结晶的锂配合物。这些已使用,其特征在于X射线衍射数据[李2-C(森达3)2 C ^ 5 ħ 4 N} 2-CH(森达3)2 C ^ 5 ħ 4 N}](1),[Li [2-C(SiMe 3)2 C 5 H 4 N]} 2 ](2),[Li(tmen)2-C(SiMe 3)2 C 5 H 4 N}](3),[Li(OEt 2)[2-CH(SiMe 3)C 5 H 4 N]} 2 ](4),[Li(tmen)[2-CH(SiMe 3)C 5 H 4 N] } 2 ](5)和[Li(sp)2-CH(SiMe 3)C 5 H 4 N}](6)。在(1),(3),(4)和(6)烃基充当η
Preparation and Regioselective Magnesiation or Lithiation of Bis(trimethylsilyl)methyl-Substituted Heteroaryls for the Generation of Highly Functionalized Heterocycles
作者:Thomas Klatt、Veronika Werner、Marina G. Maximova、Dorian Didier、Yitzhak Apeloig、Paul Knochel
DOI:10.1002/chem.201500627
日期:2015.5.18
A wide range of bis(trimethylsilyl)methyl (BTSM)‐ substituted heteroaryl derivatives has been prepared by using Kumada–Corriu or Negishi cross‐coupling reactions. The regioselective lithiation or magnesiation of these building blocks bearing a bulky BTSM group by using magnesium or lithium 2,2,6,6‐tetramethylpiperidide bases followed by quenching reactions with different electrophiles provides various