Addition reactions and diazomethane capture by the intramolecular P–O–B FLP: tBu₂POBcat

Abstract

FLPs, R2POBcat (R = tBu 1, Mes 2), are shown to react with a variety of substrates including diazomethanes.

A review of quantum chemical studies of Frustrated Lewis Pairs

“…Zhu et al 42 have reported the formation of several heterocycles by addition reactions of POB based intramolecular FLPs (R2POBcat) with small molecules like PhOH, CO2, CS2, PhNCO, MesCNO, O2, 9,10-phenanthrenedione, and diazomethanes.…”

Synthesis of a C(sp2)‐bridged Phosphine‐Borane by Ionic Coupling

“…Over the years, a wide library of ambiphilic compounds has been developed, in particular with phosphines as Lewis basic sites. A number of spacers varying in size and rigidity have been investigated, and P^E compounds of type I – IV (E = B, Al, Si, Sn…‐based Lewis acids) featuring a one‐atom spacer (^ = C, N, O) are an important subclass of ambiphilic derivatives (Figure ) …”

“…[5a] Later on, Ia was shown by Zargarian and Fontaine to display ambiphilic behavior upon coordination to transition metals. Since 2006, increasing interest has been devoted to such P^E compounds, in particular to C(sp 2 )‐bridged derivatives of type II , and most recently, to O‐bridged species of type IV …”

“…A number of spacers varying in size and rigidity have been investigated, and P ∧ E compounds of type I-IV (E = B, Al, Si, Sn…-based Lewis acids) featuring a one-atom spacer ( ∧ = C, N, O) are an important subclass of ambiphilic derivatives (Figure 1). [4][5][6][7][8][9][10][11] The nitrogen-bridged compound IIIa reported by Brey et al in 1966 was one of the first ambiphilic phosphine to be synthetized. [4] About 2 decades later, Karsch et al prepared the CH 2 -bridged phosphine-alane Ia and substantiated its head-totail dimeric structure.…”

“…[5b-5d] Since 2006, increasing interest has been devoted to such P ∧ E compounds, in particular to C(sp 2 )bridged derivatives of type II, [7][8][9][10] and most recently, to Obridged species of type IV. [11] Among one-atom-bridged ambiphilic derivatives, vinyl phosphines of type II occupy a forefront position ( Figure 2). The short and rigid C(sp 2 ) spacer imparts geometric constraints (preventing the formation of strong intramolecular PǞE interactions) and at the same time preorganizes the Lewis pair.…”