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)
Catalyst-Controlled Regioselectivity in the Synthesis of Branched Conjugated Dienes via Aerobic Oxidative Heck Reactions
作者:Changwu Zheng、Dian Wang、Shannon S. Stahl
DOI:10.1021/ja307371w
日期:2012.10.10
Pd-catalyzed aerobic oxidative coupling of vinylboronic acids and electronically unbiased alkyl olefins provides regioselective access to 1,3-disubstituted conjugateddienes. Catalyst-controlled regioselectivity is achieved by using 2,9-dimethylphenanthroline as a ligand. The observed regioselectivity is opposite to that observed from a traditional (nonoxidative) Heck reaction between a vinyl bromide
Pd 催化的乙烯基硼酸和电子无偏烷基烯烃的有氧氧化偶联提供了对 1,3-二取代共轭二烯的区域选择性访问。催化剂控制的区域选择性是通过使用 2,9-二甲基菲咯啉作为配体来实现的。观察到的区域选择性与从溴乙烯和烯烃之间的传统(非氧化)Heck 反应观察到的相反。DFT 计算研究表明,2,9-二甲基菲咯啉配体的空间效应促进了烯烃内部位置的 CC 键形成。
Trifluoromethylation of Allylsilanes under Copper Catalysis
作者:Satoshi Mizuta、Oscar Galicia-López、Keary M. Engle、Stefan Verhoog、Katherine Wheelhouse、Gerasimos Rassias、Véronique Gouverneur
DOI:10.1002/chem.201201707
日期:2012.7.9
Branched allylic CF3 products are accessible by copper‐catalyzed trifluoromethylation of allylsilanes with the Togni reagent I. The silyl group is critical to control the outcome of this reaction because in its absence, a product of addition between the alkene and the Togni reagent is formed preferentially. The reaction is inhibited with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) and is likely to
The application of cyclic and acyclic enol ethers as electrophiles in cross coupling reactions offers new possibilities for the preparation of functional compounds.