Nickel‐Catalyzed Conversion of Enol Triflates into Alkenyl Halides
作者:Julie L. Hofstra、Kelsey E. Poremba、Alex M. Shimozono、Sarah E. Reisman
DOI:10.1002/anie.201906815
日期:2019.10.14
A Ni-catalyzed halogenation of enol triflates was developed and it enables the synthesis of a broad range of alkenyl iodides, bromides, and chlorides under mild reaction conditions. The reaction utilizes inexpensive, bench-stable Ni(OAc)2 ⋅4 H2 O as a precatalyst and proceeds at room temperature in the presence of sub-stoichiometric Zn and either 1,5-cyclooctadiene or 4-(N,N-dimethylamino)pyridine
开发了镍催化的烯醇三氟甲磺酸酯卤化反应,能够在温和的反应条件下合成多种烯基碘化物、溴化物和氯化物。该反应使用廉价、实验室稳定的 Ni(OAc)2·4 H2 O 作为预催化剂,并在亚化学计量的 Zn 和 1,5-环辛二烯或 4-(N,N-二甲基氨基) 存在下在室温下进行吡啶。
Cobalt-Catalyzed Alkenylzincation of Unfunctionalized Alkynes
作者:Junliang Wu、Naohiko Yoshikai
DOI:10.1002/anie.201508262
日期:2016.1.4
While transition metal catalyzed addition reactions of arylmetal reagents to unfunctionalized alkynes have been extensively developed in the last decade, analogous reactions using alkenylmetal reagents remain rare regardless of their potential utility for the synthesis of unsymmetrical 1,3‐dienes. Reported herein is the development of a cobalt/diphosphine catalyst which promotes efficient and stereoselective
the heavier halogens (bromine and iodine) second, the scope and limitations of the halogenative phase‐transfer methodology will be discussed and compared. An extension of the fluorination/semi‐pinacol reaction to the ring‐expansion of five‐membered allylic cyclopentanols will be also described, as well as some preliminary results on substrates prone to desymmetrization will be given. Finally, the present
The present manuscript describes a high-yielding enantioselective semipinacol transposition, initiated by an electrophilic iodination event. The title transformation makes use of the anionic phase-transfer catalysis (PTC) paradigm for chirality induction. Thus, when combined appropriately, the insoluble cationic iodinating reagent S9 and the lipophilic phosphoric acid L9 act as an efficient source
Diastereoselective Synthesis of CF<sub>3</sub>- and CF<sub>2</sub>H-Substituted Spiroethers from Aryl-Fused Cycloalkenylalkanols by Photoredox Catalysis
作者:Naoki Noto、Takashi Koike、Munetaka Akita
DOI:10.1021/acs.joc.6b00953
日期:2016.8.19
Simple synthesis of CF3- and CF2H-spiroethers from aryl-fused cycloalkenylalkanols by photoredox catalysis has been developed. Modification of the fluoromethylating reagents and the photoredox catalysts leads to both CF3- and CF2H-spiroetherification. The present photocatalytic system allows us to access a variety of new anti-fluoromethylated spiroethers in a highly selective manner.