Methyl 2-triorganosilyl-3-butenoates, which are selectively obtained from the carboxylation of the corresponding allylsilanes via allylic aluminates, react with various kinds of electrophiles to give γ substituted (E)-α,β-unsaturated esters in highly regio and stereoselective manner with the aid of a Lewis acid.
Regioselective Carboxylation of Silicon-Stabilized Allylic Carbanions and the Synthetic Utility of 2-Silyl-3-butenoates
作者:Hidemitsu Uno
DOI:10.1246/bcsj.59.2471
日期:1986.8
Carbanions of allylic dimethylphenylsilanes show remarkable regioselectivity toward both carboxylation with carbon dioxide and methylation with methyl iodide. Methylation of these compounds occurred preferentialy at α position, although allyltrimethylsilane and allyltriphenylsilane are known to give γ selectivity toward the same electrophiles. Moreover, their aluminum “ate” complexes react with carbon
烯丙基二甲基苯基硅烷的碳负离子对二氧化碳的羧化和甲基碘的甲基化都显示出显着的区域选择性。这些化合物的甲基化优先发生在 α 位,尽管已知烯丙基三甲基硅烷和烯丙基三苯基硅烷对相同的亲电试剂具有 γ 选择性。此外,它们的铝“ate”复合物在 a 位置与二氧化碳发生区域选择性反应,而与烯丙基部分的甲基取代模式无关。α-羧化烯丙基硅烷被证明是酯化后 3-(甲氧基羰基)烯丙基阴离子的有用合成子。
Allylsilane Reagent‐Controlled Divergent Asymmetric Catalytic Reactions of 2‐Naphthoquinone‐1‐methide
作者:Xiangfeng Lin、Yan Liu、Can Li
DOI:10.1002/chem.202002814
日期:2020.11.6
and highly stereoselective (up to 96.5:3.5 e.r.) manner under mild conditions. Moreover, it is demonstrated that 2‐Nap‐Q‐1‐M can serve as an efficient diene for a side asymmetric Diels–Alder (D‐A) reaction. This principle can provide a straightforward access to hydrophenalene in an optically active form, which represents a structural core of various natural products and bioactive molecules.
在此,在Sc III /报道了Feng配体复合物。通过这些方法,可以在温和的条件下以直接且高度立体选择性(高达96.5:3.5 er)的方式获得各种独特取代的手性烯丙基官能化的二芳基化合物和萘并吡喃产物。此外,已证明2-Nap-Q-1-M可以用作侧面不对称Diels-Alder(D-A)反应的有效二烯。该原理可以提供光学活性形式的对苯二酚的直接途径,其代表各种天然产物和生物活性分子的结构核心。
Silver-Catalyzed Transmetalation between Chlorosilanes and Aryl and Alkenyl Grignard Reagents for the Synthesis of Tetraorganosilanes