Enantioselective Cyanation/Brook Rearrangement/C-Acylation Reactions of Acylsilanes Catalyzed by Chiral Metal Alkoxides
摘要:
New catalytic enantioselective cyanation/1,2-Brook rearrangement/C-acylation reactions of acylsilanes (4) with cyanoformate esters (7) are described. The products of the reaction are fully substituted malonic acid derivatives (8). Catalysts for this transformation were discovered via a directed candidate screen of 96 metal-ligand complexes. Optimization of a (salen)aluminum complex revealed significant remote electronic effects and concentration effects. The scope of the reaction was investigated by using a number of aryl acylsilanes and cyanoformate esters. Chemoselective reduction of the reaction products (8) afforded new enantioenriched alpha-hydroxy-alpha-aryl-beta-amino acid derivatives (32-34) and beta-lactams (35 and 36). This reaction provides a simple method for the construction of new nitrogen-containing enantioenriched chiral building blocks.
A highly stereoselective approach to tetrasubstituted (E)-β-hydroxy silyl enol ethers by addition of aryl-substituted oxiranyl anions to acylsilanes
作者:Cheng Wang、Zubao Gan、Ji Lu、Xia Wu、Zhenlei Song
DOI:10.1016/j.tetlet.2011.02.108
日期:2011.5
A highlystereoselective approach to tetrasubstituted (E)-β-hydroxy silyl enol ethers is described. The reaction proceeds via a sequential addition/[1,2]-Brook rearrangement/epoxide-opening process of aryl-substituted oxiranyl anions with acylsilanes.
Addition of TMS-Substituted Oxiranyl Anions to Acylsilanes. A Highly Stereoselective Approach to Tetrasubstituted (<i>Z</i>)-β-Hydroxy-α-TMS Silyl Enol Ethers
作者:Zhenlei Song、Leizhou Kui、Xianwei Sun、Linjie Li
DOI:10.1021/ol200116f
日期:2011.3.18
A highlystereoselective approach to novel tetrasubstituted (Z)-β-hydroxy-α-TMS silyl enol ethers is described. The reaction proceeds via a sequential addition/[1,2]-Brook rearrangement/epoxide-opening process of TMS-substituted oxiranyl anions with acylsilanes.
[1,2]-Brook rearrangement can dearomatize aromatic N-heterocycles! Through a one-pot four-step process that includes lithiation, nucleophilic addition, Brook rearrangement, and dearomatization reaction, we enable the formation of non-aromatic N-heterocycles with functional capabilities starting from readily available precursors. Subsequent functionalization reactions provide access to a diverse compound
Chemoselective Synthesis of Unsymmetrical Dithioacetals through Sequential Carbene Insertion and Acetal Exchange of Acylsilanes and Thiols under Visible Light Irradiation
作者:Wang Zhang、Dan-Ni Yang、Dou-Dou Guo、Peng Wang、Man-Yi Han
DOI:10.1021/acs.orglett.4c00133
日期:2024.2.16
motif in synthetic organic chemistry, and most existing reports discuss only symmetrical dithioacetals. Examples of unsymmetrical dithioacetals are scarce, and few general methods for the selective synthesis of these compounds exists. An intriguing visible-light-induced strategy has been established in this work for sequential reactions of S–H insertion and acetal exchange between acylsilanes and two