Electrophilic Alkylations of Vinylsilanes: A Comparison of α- and β-Silyl Effects
作者:Hans A. Laub、Herbert Mayr
DOI:10.1002/chem.201303215
日期:2014.1.20
benzhydrylium‐based nucleophilicity scale. The vinylsilane H2CC(CH3)(SiMe3), which is attacked by electrophiles at the CH2 group, reacts one order of magnitude faster than propene, indicating that α‐silyl‐stabilization of the intermediate carbenium ion is significantly weaker than α‐methyl stabilization because H2CC(CH3)2 is 103 times more reactive than propene. trans‐β‐(Trimethylsilyl)styrene, which is attacked
CF3 on C: Trifluoromethylation of allylsilane derivatives was accomplished through the use of CuI and Togni's reagent (1) under mild conditions. The reaction of allylsilanes without a substituent in the 2‐position gave vinylsilane derivatives, while 2‐substituted allylsilanes afforded desilylated products. The utility of the products was demonstrated through their further transformation.
Enantioselective Synthesis of α-Allyl Amino Esters via Hydrogen-Bond-Donor Catalysis
作者:Andrew J. Bendelsmith、Seohyun Chris Kim、Masayuki Wasa、Stéphane P. Roche、Eric N. Jacobsen
DOI:10.1021/jacs.9b05556
日期:2019.7.24
diastereoselec-tive synthesis of α-allyl amino esters. The optimized protocol provides access to N-carbamoyl-protected amino esters via nucleophilic allyla-tion of readily accessible α-chloro glycinates. A variety of useful α-allyl amino esters were prepared-including crotylated products bearing vicinal stereocenters that are inaccessible through enolate alkylation-with high enantioselectivity (up to 97% ee)
Visible Light-Induced Methoxycarbonyldifluoromethylation of Trimethylsilyl Enol Ethers and Allyltrimethylsilanes with FSO<sub>2</sub>
CF<sub>2</sub>
CO<sub>2</sub>
Me
作者:Wei Yu、Yao Ouyang、Xiu-Hua Xu、Feng-Ling Qing
DOI:10.1002/cjoc.201800318
日期:2018.11
omethylation of trimethylsilyl enol ethers with FSO2CF2CO2Me in the presence of fac‐Ir(ppy)3 was developed. This reaction provided a practical strategy for the construction of various α‐CF2CO2R aromatic ketones, which are difficult to access by other methods. Furthermore, a series of methoxycarbonyldifluoromethylated allylic compounds could also be obtained from allyltrimethylsilanes using the same
在fac -Ir(ppy)3存在下,用FSO 2 CF 2 CO 2 Me对三甲基甲硅烷基烯醇醚进行了光催化甲氧基羰基二氟甲基化反应。该反应的各种α-CF的构造提供了一种实用的策略2 CO 2 - [R芳族酮,这是难以通过其它方法获得。此外,也可以使用相同策略从烯丙基三甲基硅烷获得一系列甲氧基羰基二氟甲基化的烯丙基化合物。所得的含CF 2 CO 2 R的产品是有用的组成部分,在药物化学和材料科学中具有潜在的价值。
Gold-Catalyzed Deoxygenated Cyclization of <i>cis</i>-2,4-Dien-1-als with Regioselective Addition of Two Nucleophiles. One-Pot Synthesis of Highly Functionalized Cyclopentene Framework
作者:Chung-Chang Lin、Tse-Min Teng、Arjan Odedra、Rai-Shung Liu
DOI:10.1021/ja069171f
日期:2007.4.1
We report a new gold-catalyzed deoxygenated cyclization of cis-2,4-dien-1-als with external nucleophiles at ambient temperatures, which leads to a 1,4-double nucleophilic addition to the newly formed cyclopentene ring. The use of this cyclization is reflected not only by its compatibility with a wide scope of nucleophiles, but also by a facile construction of complex frameworks in diversified approaches