dialkoxycarbonylation of various aromatic and aliphatic alkynes affording a wide range of 1,4-dicarboxylic acid diesters in high yields and selectivities. Kinetic studies suggest the generation of 1,4-dicarboxylic acid diesters via cascade hydroesterification of the corresponding alkynes. Based on these investigations, the chemo- and regioselectivities of alkyne carbonylations can be controlled as shown by switching
Hydrogen Atom Transfer Reactions via Photoredox Catalyzed Chlorine Atom Generation
作者:Samantha Rohe、Avery O. Morris、Terry McCallum、Louis Barriault
DOI:10.1002/anie.201810187
日期:2018.11.26
waste‐limiting, and atom‐economical. The catalytic generation of chlorineatoms from chloride ions is one of the most challenging redox processes, where the requirement of harsh and oxidizing reaction conditions renders it seldom utilized in synthetic applications. We report the mild, controlled, and catalytic generation of chlorineatoms as a new opportunity for access to a wide variety of hydrogen atom transfer
Generation of Functionalized Alkyl Radicals via the Direct Photoexcitation of 2,2′-(Pyridine-2,6-diyl)diphenol-Based Borates
作者:Yusuke Miyamoto、Yuto Sumida、Hirohisa Ohmiya
DOI:10.1021/acs.orglett.1c01996
日期:2021.8.6
was developed for the purpose of generating radicals via direct photoexcitation. These borates were prepared using 2,2′-(pyridine-2,6-diyl)diphenol as a tridentate ligand together with organoboronic acids or potassium trifluoroborates. The ready availability of organoboroncompounds is a significant advantage of this direct photoexcitation protocol. The excited states of these borates can also serve
The generation of tertiary, secondary, and primary alkyl radicals has been achieved by the direct visible-light excita-tion of a boracene-based alkylborate. This system is based on the photophysical properties of the organoboron mole-cule. The protocol is applicable to decyanoalkylation, Giese addition, and nickel-catalyzed carbon-carbon bond for-mations such as alkyl-aryl cross-coupling or vicinal
palladium‐catalyzed oxidative bis‐alkoxycarbonylation reaction of olefins. The most active catalyst was formed in situ from bis(9‐anthryl)‐2,3‐dimethyl‐1,4‐diazabutadiene and palladium(II) trifluoroacetate [Pd(TFA)2]. This catalytic system was able to selectively convert olefins into succinicdiesters in good yields (up to 97%) and low catalyst loading (up to 0.5 mol%) under mild reaction conditions [4 bar