Synthesis of phosphinoferrocene amides and thioamides from carbamoyl chlorides and the structural chemistry of Group 11 metal complexes with these mixed-donor ligands

Abstract

The reaction of in situ generated 1'-(diphenylphosphino)-1-lithioferrocene with carbamoyl chlorides, ClC(E)NMe2, affords the corresponding (thio)amides, Ph2PfcC(E)NMe2 (E = O (), S (); fc = ferrocene-1,1'-diyl). These compounds as well as their analogues, Ph2PfcC(O)NHMe () and Ph2PfcC(O)NH2 (), prepared from 1'-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf) were studied as ligands for the Group 11 metal ions. In the reactions with [Cu(MeCN)4][BF4], the amides give rise to bis-chelate complexes of the type [Cu(L-κ(2)O,P)2][BF4]. Similar products, [Ag(L-κ(2)O,P)2]ClO4, are obtained from silver(i) perchlorate and , or . In contrast, the reaction of AgClO4 with produces a unique molecular dimer [Ag()(ClO4-κO)]2, where the metal centres are bridged by the sulfur atoms of the P,S-chelating thioamides. The reactions of with [AuCl(tht)] (tht = tetrahydrothiophene) afford the expected gold(i)-phosphine complexes, [AuCl(L-κP)], containing uncoordinated (thio)amide moieties. Hemilabile coordination of the phosphinoamide ligands in complexes with the soft Group 11 metal ions is established by the crystal structure of a solvento complex, [Cu(-κ(2)O,P)(-κP)(CHCl3-κCl)][BF4], which was isolated serendipitously during an attempted crystallisation of [Cu(-κ(2)O,P)2][BF4]. All of the compounds are characterised by spectroscopic methods, and the structures of several representatives of both the free phosphinoamides and their complexes are determined by X-ray diffraction analysis and further studied by DFT calculations and cyclic voltammetry.

Probing the Influence of Phosphine Substituents on the Donor and Catalytic Properties of Phosphinoferrocene Carboxamides: A Combined Experimental and Theoretical Study

“…The PSe bond lengths vary by less than approximately 0.02 Å in the entire series and compare well with the values reported for dppfSe 2 and analogous compounds . Likewise, the parameters describing the amide moieties do not substantially differ from those determined for 1d , 1c , and 5c (see above).…”

“…Interatomic distances and angles determined for 1c and 5c (Table ) generally parallel those reported previously for amide 1d . Differences between the structures of 1c and 5c are expectedly found in their phosphine groups.…”

“…In the last step, the borane protecting group was removed by treatment with 1,4-diazabicyclo[2.2.2]­octane (DABCO) to give target amides 1a – c . To complete the series, compound 1d was prepared by the amidation of Hdpf with methylamine as described earlier and, for the sake of comparison, was further converted to the corresponding BH 3 adduct 5d by reaction with BH 3 ·SMe 2 .…”

“…With the goal of expanding the family of phosphinoferrocene carboxamide donors by variation of their phosphine parts, we decided to first evaluate the influence of the phosphine substituents on the stereoelectronic and catalytic properties of these hybrid ligands. To this end, we prepared and studied a series of compounds bearing different substituents on the phosphorus atom, akin to the recently described Hdpf-amide 1d (Chart ).…”

From 2- to 3-Substituted Ferrocene Carboxamides or How to Apply Halogen “Dance” to the Ferrocene Series

“…We considered and evaluated two routes toward these substrates: ferrocene deprotometalation followed by trapping using dialkylcarbamoyl chlorides (route A) and amide formation from ferrocenecarboxylic acid (route B) . As shown in Table , the two routes work in similar yields although route A provides the ferrocenecarboxamides 1 – 4 in only one step from cheap ferrocene.…”