Magnetic copper ferrite catalyzed homo‐ and cross‐coupling reaction of terminal alkynes under ambient atmosphere

Abstract

The application of non-toxic and magnetically separable nano-CuFe 2 O 4 as an efficient catalyst for oxidative homo-and cross-coupling reaction of terminal alkynes is described. A wide range of symmetrical and unsymmetrical 1,3-diynes have been synthesized in moderate to good yields under ambient atmosphere. The nano CuFe 2 O 4 can be recovered with a magnet and reused at least five consecutive cycles with no appreciable loss of its catalytic activity.

A walk around the application of nanocatalysts for cross-dehydrogenative coupling of C–H bonds

“…Magnetically separable nano-CuFe 2 O 4 (with an average particle size of 30-35 nm) was also found to be active catalyst towards the oxidative cross-coupling of aromatic alkynes 62 with terminal alkynes 63 at room temperature. 74 The reaction was performed under open air using pyrrolidine as a base, tolerated a number of important functional groups (e.g., F, Cl, Br, OMe, CO 2 Me, and OH), and provided the expected 1,3-diynes 64 in moderate yields (Scheme 27). Interestingly, the catalyst can be easily separated from the reaction mixture by using an external magnetic eld, and its efficiency remains unchanged even aer recycling over ve runs.…”

“…Scheme 27 (a) Oxidative cross-coupling of 4-methoxyphenylacetylene 59 with aromatic terminal alkynes 60 catalyzed by Au/SBA-15-amine; 73 (b) CuFe 2 O 4 -catalyzed cross-dehydrogenative coupling of 62 with 63 74. …”