Palladium-Catalyzed Methylation of Alkynyl C(sp)–H Bonds with Dimethyl Sulfonium Ylides
摘要:
A novel palladium-catalyzed methylation protocol for the synthesis of methyl-functionalized internal alkynes has been established. This methylation method is achieved through a C(sp)-C(sp(3)) bond formation process and represents a new synthetic application of sulfonium ylides.
Reactions of carbonyl-stabilized sulphonium ylides with grignard reagents
作者:H. Nozaki、K. Nakamura、M. Takaku
DOI:10.1016/s0040-4020(01)82900-8
日期:——
Sulphonium diacylmethylides RR′-;(COR′)2 react with R′'‴MgX to afford ketones R′COR′'′, if either R′' or R′'′ has an α-hydrogen. In the absence of this, for example, the reaction of R(Me)(COPh)2 with PhMgBr results in elimination of the S-;Me and gives a product RSC(COPh2. If R, R′, R′' and R‴ are all Ph groups, benzophenone and Ph2HCOPh are formed. The reaction of phenacylides R(Me)HCOPh with
Ruthenium-Catalyzed Chemoselective N–H Bond Insertion Reactions of 2-Pyridones/7-Azaindoles with Sulfoxonium Ylides
作者:Xiaofeng Liu、Ying Shao、Jiangtao Sun
DOI:10.1021/acs.orglett.0c04229
日期:2021.2.5
excellent N-selectivity. The key to achieve this unprecedented N–H rather than O–H insertionreaction is the use of CpRu(PPh3)2Cl as the catalyst and sulfoxoniumylides as the alkylation reagents. Moreover, this protocol is also amenable to 7-azaindoles by slightly varying the reaction conditions. Furthermore, sulfonium ylides are also suitable alkylation reagents, providing the N-alkylated 2-pyridones in
ZnCl
<sub>2</sub>
‐Catalyzed [4+1] Annulation of Alkylthio‐Substituted Enaminones and Enaminothiones with Sulfur Ylides
作者:Yuan He、Jiang Lou、Zhengkun Yu、Yong‐Gui Zhou
DOI:10.1002/chem.201905483
日期:2020.4.16
in the synthesis of potentially bioactive compounds and functional materials. Herein, we report an efficient Lewis acid ZnCl 2 -catalyzed [4+1] annulation of alkylthio-substituted enami-nones, that is, α -oxo ketene N,S -acetals, with sulfur ylides, affording 2-acyl-3-aminofuran derivatives. In a similar fashion, [4+1] annulation of the corresponding enaminothiones, that is, α -thioxo ketene N,S -acetals
Catalytic Asymmetric [3+1]‐Cycloaddition Reaction of Ylides with Electrophilic Metallo‐enolcarbene Intermediates
作者:Yongming Deng、Lynée A. Massey、Peter Y. Zavalij、Michael P. Doyle
DOI:10.1002/anie.201704069
日期:2017.6.19
first asymmetric [3+1]‐cycloaddition was successfully achieved by copper(I) triflate/double‐sidearmed bisoxazoline complex catalyzed reactions of β‐triisopropylsilyl‐substituted enoldiazo compounds with sulfur ylides. This methodology delivered a series of chiral cyclobutenes in good yields with high enantio‐ and diastereoselectivities (up to 99 % ee, and >20:1 d.r.). Additionally, the [3+1]‐cycloaddition
(IX), and the reaction with tosyl chloride yields a O-tosylated sulphonium salt (XI). These new salts are stable and can be isolated without cleavage of the phenyl—sulphur bond. Heating at 160° results in a novel rearrangement of VII into (Z)-α-phenoxy-β-phenylthiostyrene (XV). The related reactions of iodonium ylides have been investigated.