reaction for the first time. A catalyst-free three-component synthesis of α-aryl- and α-alkenylglycine derivatives starting from glyoxylicacid, sulfonamides, and aryl- or alkenylboronic acids is described. This operationally simple method tolerates a broad range of functional groups and enables the generation of a wide array of α-aminoacids. Sulfonamides were utilized as amine component in the classic
Chromium(II)-Mediated Reactions of Iodonium Tetrafluoroborates with Aldehydes: Umpolung of Reactivity of Diaryl-, Alkenyl(aryl)-, and Alkynyl(aryl)iodonium Tetrafluoroborates
作者:Da-Wei Chen、Masahito Ochiai
DOI:10.1021/jo990809y
日期:1999.9.1
of iodonium salts with anhydrous chromium dichloride, followed by their nucleophilic addition to aldehydes to yield alcohols. In contrast to the reaction of aryl and alkenyl halides with chromium dichloride, these iodonium salts are so active that organochromium(III) could be generated without using a nickel catalyst. Substituent effects of unsymmetrically substituteddiaryliodoniumsalts on the product
The First General and Selective Palladium(II)-Catalyzed Alkoxycarbonylation of Arylboronates: Interplay among Benzoquinone-Ligated Palladium(0) Complex, Organoboron, and Alcohol Solvent
作者:Yoshihiko Yamamoto
DOI:10.1002/adsc.200900836
日期:2010.2.15
Methoxycarbonylation of aryl- and alkenylboron compounds was performed using the palladium(II) acetate/triphenylphosphine [Pd(OAc)2/PPh3] catalyst with p-benzoquinone as a stoichiometric oxidant in methanol at ambient temperature to obtain the corresponding methyl esters in good yields. A wide variety of functional groups including various carbonyl functionalities, nitrile, nitro, sulfone, and unprotected
Gold-Catalyzed Allylation of Aryl Boronic Acids: Accessing Cross-Coupling Reactivity with Gold
作者:Mark D. Levin、F. Dean Toste
DOI:10.1002/anie.201402924
日期:2014.6.10
the absence of a sacrificial oxidant is described. Vital to the success of this method is the implementation of a bimetallic catalyst bearing a bis(phosphino)amine ligand. A mechanistic hypothesis is presented, and observable transmetalation, CBr oxidative addition, and CC reductive elimination in a model gold complex are shown. We expect that this method will serve as a platform for the development
描述了在没有牺牲氧化剂的情况下由金催化的sp 3 –sp 2 C C 交叉偶联反应。该方法成功的关键是采用带有双(膦基)胺配体的双金属催化剂。提出了一个机制假设,并显示了模型金配合物中可观察到的金属转移、C Br 氧化加成和 C C 还原消除。我们预计这种方法将成为开发涉及氧化还原活性金催化剂的新型转化的平台。
Apparent 6‐
<i>endo‐</i>
trig Carbofluorination of Alkenes Enabled by Palladium‐Based Dyotropic Rearrangement
作者:Jing Gong、Qian Wang、Jieping Zhu
DOI:10.1002/anie.202211470
日期:2022.12.12
cyclization mode. Pd-catalyzed cyclization of 2-(2-alkylallyloxy)phenylboronic acid derivatives in the presence of Selectfluor 2 provides chromanes 3 with concurrent generation of a tertiary alkylfluoride function. A 5-exo-trig carbopalladation affords PdII intermediate A whose oxidation to PdIV followed by 1,2-aryl/PdIV dyotropic rearrangement and C−F bond-forming reductive elimination affords chromane