Cobalt-catalyzed annulation of styrenes with α-bromoacetic acids
作者:Tung T. Nguyen、Bao H. T. Ngo、Huy X. Le、Linh N. P. Vu、Tuong A. To、Anh N. Q. Phan、Nam T. S. Phan
DOI:10.1039/d0ra09588e
日期:——
We report a method for addition of α-bromophenylacetic acids to vinyl CC bonds in styrenes to afford γ-lactones. Reactions employed a simple cobalt catalyst Co(NO3)2·6H2O in the presence of dipivaloylmethane (dpm) ligand. Many functionalities including halogen, ester, and nitro groups were compatible with reaction conditions. If α-bromoesters were used, vinylacetates were the major products.
我们报告了一种将 α-溴苯乙酸添加到苯乙烯中的乙烯基 C C 键以提供 γ-内酯的方法。在二戊酰甲烷 (dpm) 配体存在下,反应使用简单的钴催化剂 Co(NO 3 ) 2 ·6H 2 O。许多官能团,包括卤素、酯和硝基,都与反应条件相容。如果使用 α-溴代酯,醋酸乙烯酯是主要产品。
Organo-photoredox-Catalyzed Atom-Transfer Radical Substitution of Alkenes with α-Carbonyl Alkyl Halides
作者:Goki Hirata、Taisei Shimada、Takashi Nishikata
DOI:10.1021/acs.orglett.0c03359
日期:2020.11.20
(ATRS) and carboesterification reaction of alkenes with alkyl halides has been developed using PTH as the organo-photoredox catalyst. Two types of products were obtained, depending on the additive and solvent used during the reaction. Primary, secondary, and tertiary alkyl halides reacted to give the ATRS products. This protocol has several advantages: it requires mild reaction conditions and a low catalyst
A Pyridine-Based Donor–Acceptor Molecule: A Highly Reactive Organophotocatalyst That Enables the Reductive Cleavage of C–Br Bonds through Halogen Bonding
作者:Natsuki Kato、Takeshi Nanjo、Yoshiji Takemoto
DOI:10.1021/acscatal.2c02067
日期:2022.7.1
direct, photocatalytic reductive cleavage of the C–Br bond. A wide variety of alkyl bromides including unactivated ones can be used under ambient conditions without any additional activating agents to give the C–C coupling products in good yield. Mechanistic studies indicated that the photocatalyst interacts with alkyl bromides throughhalogenbonding and that the pyridine moiety is important for the progress
A Novel Intermolecular Synthesis of γ-Lactones via Visible-Light Photoredox Catalysis
作者:Xiao-Jing Wei、Deng-Tao Yang、Lin Wang、Tao Song、Li-Zhu Wu、Qiang Liu
DOI:10.1021/ol402954t
日期:2013.12.6
Direct gamma-lactone formation via visible-light photoredox catalysis has been achieved efficiently including hydroxylalkylation of aromatic alkenes and transesterification. The present photocatalytic protocol has good regioselectivity and substrate compatibility, affording a novel way to intermolecular gamma-lactone synthesis by the reaction of styrenes with alpha-bromo esters in the absence of any external oxidants.