An enantioselective alkoxycarbonylation-amination cascade process of terminalallenes with CO, methanol, and arylamines has been developed. It proceeds under mild conditions (room temperature, ambient pressure CO) via oxidative Pd(II) catalysis using an aromatic spiroketal-based diphosphine (SKP) as a chiral ligand and a Cu(II) salt as an oxidant and affords a wide range of α-methylene-β-arylamino
Copper-Catalyzed Difunctionalization of Allenes with Sulfonyl Iodides Leading to (<i>E</i>)-α-Iodomethyl Vinylsulfones
作者:Ning Lu、Zhiguo Zhang、Nana Ma、Conghui Wu、Guisheng Zhang、Qingfeng Liu、Tongxin Liu
DOI:10.1021/acs.orglett.8b01765
日期:2018.7.20
A highly regioselective iodosulfonylation of allenes in the presence of CuI and 1,10-phenanthroline has been developed for the synthesis of various useful (E)-α-iodomethyl vinylsulfones in moderate to excellent yields. This practical reaction is fast, operationally simple, and in particular, proceeds under very mild conditions to afford the target products with high regio- and stereoselectivity. The
Intermolecular Allene Functionalization by Silver-Nitrene Catalysis
作者:Manuel R. Rodríguez、María Besora、Francisco Molina、Feliu Maseras、M. Mar Díaz-Requejo、Pedro J. Pérez
DOI:10.1021/jacs.0c04395
日期:2020.7.29
Under silver catalysis conditions, using [Tp*,BrAg]2 as the catalyst precursor, allenes react with PhI=NTs in the first example of efficient metal-mediated intermolecular nitrenetransfer to such substrates. The nature of the substituent at the allene seems crucial for the reaction outcome since arylallenes are converted into azetidine derivatives whereas methylene aziridines are the products resulting
Stereoselective Functionalization of Racemic Cyclopropylzinc Reagents via Enantiodivergent Relay Coupling
作者:Lun An、Fei-Fei Tong、Shu Zhang、Xingang Zhang
DOI:10.1021/jacs.0c04462
日期:2020.7.8
cyclopropylzinc reagents. This strategy relies on a one-pot, two-step enantiodivergent relay coupling (EDRC) process of the racemic cis-cyclopropylzinc reagents with two different electrophiles, which involves kinetic resolution of racemic cis-cyclopropylzinc reagents through a nickel-catalyzed enantioselective coupling with alkyl electrophiles, followed by a stereospecific relay coupling of the remaining
Spectroscopic and Calorimetric Studies on the Mechanism of Methylenecyclopropane Rearrangements Triggered by Photoinduced Electron Transfer
作者:Hiroshi Ikeda、Kimio Akiyama、Yasutake Takahashi、Tatsuo Nakamura、Satoshi Ishizaki、Yukio Shiratori、Hitoshi Ohaku、Joshua L. Goodman、Abdelaziz Houmam、Danial D. M. Wayner、Shozo Tero-Kubota、Tsutomu Miyashi
DOI:10.1021/ja0277982
日期:2003.7.1
cation radical (6.+) and the corresponding diradical (6..), respectively. These intermediates are also detected, respectively, by steady state and nanosecond time-resolved EPR with chloranil or anthraquinone as a sensitizer. The degeneraterearrangement of d(2)-1 thus proceeds via these twodifferenttypes of intermediates in a cation radical cleavage-diradical cyclization mechanism. Energetics based