Insertion of heteroallenes into the rhenium–hydride bond

Dithioformato [Re{η2-SC(H)S}(NO)P3]BPh4 (1), thioformamido [Re{η2-RNC(H)S}(NO)P3]BPh4 (2) (R = Et, p-tolyl), formamido [Re{η2-PhNC(H)O}(NO)P3]BPh4 (3) and formamidinato [Re{η2-p-tolylNC(H)Np-tolyl}(NO)P3]BPh4 (4) (P = PPh2OEt) complexes were prepared by allowing the hydride ReH2(NO)P3 to react first with triflic acid and then with the appropriate heteroallene CS2, RNCS, PhNCO and p-tolylNCNp-tolyl. Treatment of the ReH2(NO)L(PPh3)2 [L = P(OEt)3, PPh(OEt)2] and ReH2(NO)(PPh3)3 hydrides first with triflic acid and then with isothiocyanate RNCS (R = Et, p-tolyl) gave the [Re{η2-RNC(H)S}(NO){P(OEt)3}(PPh3)2]BPh4 (5, 6) and [Re(η2-RNC(H)S)(NO)(PPh3)3]BPh4 (7) derivatives. Depending on the nature of the phosphite, instead, the reaction of ReH2(NO)L(PPh3)2 and ReH2(NO)(PPh3)3 hydrides first with CF3SO3H and then with isocyanate R1NCO (R1 = Ph, p-tolyl) gave the chelate [Re{η2-R1NC(H)O}(NO){P(OEt)3}(PPh3)2]BPh4 (8) and [Re{η2-R1NC(H)O}(NO)(PPh3)3]BPh4(10) complexes with P(OEt)3 or PPh3, while the η1-coordinate [Re{η1-RNC(H)S}(NO){PPh(OEt)2}2(PPh3)2]BPh4 (9) derivative was obtained with the PPh(OEt)2 phosphite ligand. η1-Coordinate dithioformato [Re{η1-SC(H)S}(NO){PPh(OEt)2}2(PPh3)2]BPh4 (11) and formato [Re{η1-OC(H)O}(NO){PPh(OEt)2}2(PPh3)2]BPh4 (12) complexes, as well as the formamidinato [Re{η2-p-tolylNC(H)Np-tolyl}(NO){P(OEt)3}(PPh3)2]BPh4 (13) derivative were also prepared.

Graphical abstractThe synthesis of dithioformato [Re{η2-SC(H)S}(NO)P3]BPh4, thioformamido [Re{η2-RNC(H)S}(NO)P3]BPh4, formamido [Re{η2-PhNC(H)O}(NO)P3]BPh4 and formamidinato [Re{η2-p-tolylNC(H)Np-tolyl}(NO)P3]BPh4 (4) complexes was achieved by reacting the hydride ReH2(NO)P3 first with triflic acid and then with the appropriate heteroallene. Insertion of carbon dioxide into the rhenium–hydride bond was also observed giving the η1-coordinate [Re{η1-OC(H)O}(NO){PPh(OEt)2}2(PPh3)2]BPh4 formato derivative.Figure optionsDownload full-size imageDownload as PowerPoint slide