Regioselective Iodoazidation of Alkynes: Synthesis of α,α-Diazidoketones
摘要:
Aryl alkyl alkynes reacted with N-iodosuccinimide (NIS) and trimethylsilyl azide (TMSN3), leading to α,α-diazidoketones via the regioselective addition of IN3 to alkynes. Huisgen cyclization of α,α-diazidoketones generated bis-triazole compounds.
Visible-light-enabled aerobic synthesis of benzoin bis-ethers from alkynes and alcohols
作者:Wen-Long Lei、Biao Yang、Qing-Bao Zhang、Pan-Feng Yuan、Li-Zhu Wu、Qiang Liu
DOI:10.1039/c8gc02766h
日期:——
atom-economical and good regioselective method for the synthesis of benzoin bis-ethers has been developed via directly using readily available alkynes and alcohols as raw materials under visible light irradiation. The protocol utilizes commercial Mes-Acr+ClO4− as an organophotoredox catalyst and air (O2) as a green sustainable reagent. A range of benzoin bis-ether derivatives were easily and efficiently obtained
Synthesis of α-Acyloxyketone Derivatives <i>via</i> the Platinum-Catalyzed Migration of Propargylic Esters
作者:Chihiro Tsukano、Sho Yamamoto、Yoshiji Takemoto
DOI:10.1248/cpb.c15-00417
日期:——
The synthesis of α-acyloxyketones via the migration of a propargylic ester followed by the intramolecular nucleophilic addition of the resulting allene was achieved using a cationic platinum catalyst. The optimized conditions for this transformation were determined to be 3 mol% of Pt(cod)Cl2, 3 mol% of AgNTf2, and 3 eq of water in toluene at 100°C, and these conditions were successfully applied to the synthesis of a wide variety of α-aryl-α-acyloxyketones. The mechanism of this reaction was evaluated in detail based on the results of isotope labeling experiments using H218O.
Copper(I)-Catalyzed Regio- and Chemoselective Single and Double Addition of Nucleophilic Silicon to Propargylic Chlorides and Phosphates
作者:Chinmoy K. Hazra、Martin Oestreich
DOI:10.1021/ol301827t
日期:2012.8.3
Copper(I)-catalyzed propargylic substitution of linear precursors with (Me2PhSi)2Zn predominantly yields the γ isomer independent of the propargylic leaving group. The thus formed allenylic silane reacts regioselectively with another equivalent of (Me2PhSi)2Zn, yielding a bifunctional building block with allylic and vinylic silicon groups. The reaction rates of both steps are well-balanced for chloride
A metal‐free, room temperature protocol for the regioselectivechloroazidation of internalalkynes is disclosed. The reactions of internalalkynes with trimethylsilyl azide (TMSN3) in the presence of 1,3‐dichloro‐5,5‐dimethylhydantoin (DCDMH) afforded the corresponding chloroazidoalkenes in good yields. This reaction has good functional group tolerance and is operationally simple.