Synthesis of 2-Alkynyltetrahydrofuran Derivatives from Tetrahydrofuran and Alkynyl Bromides
摘要:
An efficient and general method for the synthesis of 2-alkynyltetrahydrofuran was developed. The regioselective functionalization of the C(sp(3))-H bond adjacent to an oxygen atom with various alkynyl bromides has been achieved under transition-metal-free reaction conditions. Sodium fluoride was found, for the first time, to promote the efficient functionalization process remarkably. Moreover, 1,2-dibromostyrenes were also found to be effective in this method forming 2-alkenyltetrahydrofurans.
Photochemical Functionalization of Heterocycles with EBX Reagents: C−H Alkynylation versus Deconstructive Ring Cleavage**
作者:Errika Voutyritsa、Marion Garreau、Maroula G. Kokotou、Ierasia Triandafillidi、Jérôme Waser、Christoforos G. Kokotos
DOI:10.1002/chem.202002868
日期:2020.11.11
The development of novel methodologies for the functionalization of saturated heterocycles is highly desirable. Herein, we report a cheap and efficient photochemical method for the C−H functionalization of saturated O‐heterocycles, as well as the deconstructive ring‐cleavage of S‐heterocycles, employing hypervalent iodine alkynylation reagents (ethynylbenziodoxolones, EBX). This photochemical alkynylation
Functionalisation of ethereal-based saturated heterocycles with concomitant aerobic C–H activation and C–C bond formation
作者:Nehaal Ahmed、Richard J. Spears、Tom D. Sheppard、Vijay Chudasama
DOI:10.1039/d2sc01626e
日期:——
emphasis on sustainable synthesis, aerobic C–Hactivation (the use of oxygen in air to activateC–H bonds) represents a highly attractive conduit for the development of novel synthetic methodologies. Herein, we report the air mediated functionalisation of various saturated heterocycles and ethers via aerobically generated radical intermediates to form new C–C bonds using acetylenic and vinyl triflones as radical