A diphos‐Complex of P^⊕: The 1,1,3,3‐Tetraphenyl‐1λ⁵,2λ³,3λ⁵‐triphospholenyl Cation

Abstract

bond of the substrate is activated by ring strain. Thus, e. 9.. 3,3-dimethylcyclopropene 1 is cyclooligomerized, sometimes highly chemoselectively, on palladium(0) catalysts"! Palladacycloalkanes of various ring size have been discussed as intermediates.We have now succeeded in preparing five-and ninemembered palladacycloalkanes in stoichiometric reactions, and have simulated a catalytic cycle by their thermal decomposition. We synthesized the colorless palladacycloalkanes 3 to 5 by reaction of the dark-red complex (q3-al-0 Verlag Chemie GmhH. 6940 Weinheim. 1982 0S70-083~/82/~101-0064 $ OZ,SO/O Angeu,. Chem. I I~I . Ed. Engf. 21 (19821 No. I

The identification of some novel four‐membered ring cyclic triphosphenium ions in solution

“…Since the report of the first cyclic triphosphenium ion by Schmidpeter and co-workers in 1982 [1], several of these species with three linked phosphorus atoms in a heterocyclic ring and an overall positive charge have been described for five-, six-, or seven-membered rings [2][3][4][5][6][7][8]. While neutral four-membered heterocycles containing three linked phosphorus atoms and carbon substituents are known [9], however, the only cationic examples have two -NEt 2 or -morpholino groups on each of the outer phosphorus atoms, where the nitrogen atoms will assist in delocalization of the formal positive charge [10].…”

“…While neutral four-membered heterocycles containing three linked phosphorus atoms and carbon substituents are known [9], however, the only cationic examples have two -NEt 2 or -morpholino groups on each of the outer phosphorus atoms, where the nitrogen atoms will assist in delocalization of the formal positive charge [10]. Cyclic triphosphenium ions may be readily recognized in solution by the low frequency 31 P NMR shift of the central bare (P A ) phosphorus atom, and the large 1 J PP coupling constant [1][2][3][4][5][6][7][8]. Early experiments with bisdiphenylphosphinomethane (dppm) and PCl 3 , with or without the presence of SnCl 2 , yielded no NMR evidence for ring formation, although some interesting color changes to yellow and then orange were observed, even at low temperature (195 K) [11].…”

Reaction of a cyclic triphosphenium ion with triflic acid and SnX2 (X = Br or Cl): A 31P NMR study

“…The cyclic triphosphenium ion 1 was formed as its hexahalogenostannate(IV) salt via (1) an approximately 1:1:1 reaction between dppb, PX 3 , and SnX 2 (Eq. (1) (Fig.…”

“…Protonation of the cyclic triphosphenium ions [1][2][3][4][5][6] derived from 1,2-bis-diphenylphosphinoethane (dppe) or tetraphos by a mixture of t BuCl and AlCl 3 was first demonstrated by Schmidpeter and coworkers [2,7]. In a recent paper, we have extended this work considerably, having protonated a wide variety of cyclic triphosphenium ions to the corresponding di-ium dications, using either [8].…”

Preparation and Characterization of a Ligand‐Stabilized Trimethylphosphane Dication

“…Also summarized in Figure 1 are generic examples of donor-acceptor complexes that have been structurally characterized for monocations of type A, [2][3][4][5][6][7][8] B, [9][10][11][12][13] C, [1,[14][15][16][17][18] D, [19][20][21] E [22,23] and F. [24] Complexes of a phosphorus dication of type G have been proposed on the basis of spectroscopic and chemical analysis data, [25][26][27][28] but solid-state structures have been confirmed for only two examples. [6,14,18] There are no structural reports of complexes involving cations of the type H, I, J, K, L or M.…”