The phosphirenyl cation complex [W(CO)5{PC(Ph)C(Ph)}]+ (2) is formed by chloride abstraction from the chlorophosphirene complex [W(CO)5{P(Cl)C(Ph)C(Ph)}] (1) with excess AlCl3. The phosphirenyl triflate complex [W(CO)5{P(OSO2CF3)C(Ph)C(Ph)}] (3) is formed by reaction of the chlorophosphirene complex with AgOSO2CF3 and is in equilibrium with and typically reacts in the same fashion as the phosphirenyl cation. Reaction of 3 with diethylaniline or anisole leads to electrophilic aromatic substitution preferentially at the para position. Reaction with N,N-dimethyl-p-toluidine, in which the para position is blocked, leads to exclusive ortho substitution. The resulting 1,2-substituted arene can adopt a P,N bidentate coordination mode if a CO is removed from tungsten via photolysis. Compound 3 reacts with aromatic heterocycles thiophene, furan, and pyrrole, leading exclusively to substitution in the 2 position, with no evidence for P–S, P–O, or P–N bond formation. Reaction with indole led to substitution at the 3...
and C/2 w -) O oi bS >* 0- p UJ H D H H C/2 CQ D on O Z o s u. o C/2 Q Z <c » z o M H e, oi O C/2 CQ < … substitution at C-2, the C-4 resonance is least affected, whereas the C-4 and C-5 resonances … electron-withdrawing substituent at the 2 position leads to electrophilic substitution at positions
Tellurophene C-2 118.2 C-3 107.2 J C-2.H-2 184 J C-3.H-3 170 J C-2.H-3 (7.6) J C-2.H-4 (7.6) J C-2.H-5 (7 … acid of imidazole are greater at the 2-position than at the 4- position and thus bear no … as nucleophiles attack at the 2- position and electrophiles at the 4-position. The results
Everything we examined (3) — 2 independent sources
This check searched the claim as stated. It did not run a separate search for evidence against it.