Regioselective addition/annulation of ferrocenyl thioamides with 1,3-diynes via a sulfur-transfer rearrangement to construct extended π-conjugated ferrocenes with luminescent properties

Abstract

Regioselective addition/annulation of ferrocenyl thioamides with 1,3-diynes has been developed to construct extended π-conjugated ferrocenes with luminescent properties.

1,3‐Diynes: A Versatile Precursor in Transition‐Metal Catalyzed (Mediated) C−H Functionalizations

“…The authors conducted various mechanistic studies and revealed that the thiocarbonyl group undergoes addition and intramolecular sulfur-transfer rearrangement on 1,3-diyne to furnishes the ThienylFc moieties (Scheme 46). [39] The possible catalytic cycle shown in Scheme 47. The mechanism initiated with formation of active catalyst-A by ligand exchange, which subsequently coordinate and active the CÀ H activation of ferrocenyl thioamides to deliver the intermediate-B.…”

Recent Advances in Transition‐Metal‐Catalyzed C−H Functionalization of Ferrocene Amides

“…In 2020, You's group has reported a regioselective addition/ annulation sequence of ferrocenyl thioamides 162 with alkynes 163 to construct thienylferrocene (ThienylFc) structures 164, which includes rhodium-catalyzed CÀ H activation, an unusual C2-selective addition of 1,3-diyne and an unexpected intramolecular sulfur transfer rearrangement (Scheme 41A). [91] 1,4-Diphenyl-1,3-butadiynes with electron-donating and electronwithdrawing substituents in the para-or meta position of the phenyl ring afford the desired products. In this protocol, thioamide serves not only as a directing group to activate the ortho-CÀ H bond of ferrocene but also as a sulfur source to provide the indispensable heteroatom for the formation of the thiophene ring.…”

Harnessing sulfur and nitrogen in the cobalt(iii)-catalyzed unsymmetrical double annulation of thioamides: probing the origin of chemo- and regio-selectivity

“…39 A worthwhile endeavor would thus be to develop a double annulation method linked to the construction of S-enabled heterocycles through CH activation of thioamides. [40][41][42][43] Envisaging a complete coordination switch-over from 'N' to 'S' to TM would result in a metalated isothiochromenimine species B-II from mono-annulation of thioamide's S-moiety with an alkyne (Fig. 1B).…”