On the Reactivity of Phosphaalumenes towards C−C Multiple Bonds

Abstract

Heterocycles containing group 13 and 15 elements such as borazines are an integral part of organic, biomedical and materials chemistry. Surprisingly, heterocycles containing P and Al are rare. We have now utilized phosphaalumenes in reactions with alkynes, alkenes and conjugated double bond systems. With sterically demanding alkynes 1,2‐phosphaalumetes were afforded, whereas the reaction with HCCH or HCCSiMe3 gave 1,4‐phosphaaluminabarrelenes. Using styrene saturated 1,2‐phosphaalumates were formed, which reacted further with additional styrene to give different regio‐isomers of 1,4‐aluminaphosphorinanes. Using ethylene, a 1,4‐aluminaphosphorinane is obtained, while with 1,3‐butadiene a bicyclic system containing an aluminacyclopentane and a phosphirane unit was synthesized. The experimental work is supported by theoretical studies to shed light on the mechanism governing the formation of these heterocycles.

Hetero-ene Metathesis

“…The substrate scope of the (2+2) mechanisms, while broader than the other two mechanisms discussed earlier, is comparatively narrow when considering the number of double bonded main-group species available. Of particular interest are diazenes ( vide infra ) and borylenes; − heavier hetereo-enes , such as alumenes, , stannenes, and silenes also present exciting opportunities for metathesis, as a fundamental inorganic chemistry undertaking.…”

Gallaphosphene L(Cl)GaPGaL: A novel phosphinidene transfer reagent

“…Metallapnictenes RMPnR (M=B−Tl; Pn=N−Bi) containing M−Pn double bonds are isovalence‐electronic to alkenes and have received considerable interest due to their fascinating electronic structure and reactivity [10–21] . In marked contrast to borapnictenes with B−Pn (Pn=N, P, As) [10] and metallaimines with M−N double bonds (M=Al, Ga, In), [11] the heavier metallapnictenes with M−Pn double bonds (M=Al, Ga; Pn=P, As, Sb) have been reported only recently, [12–16] and their reactivity studies are still in its infancy [16–21] .…”

Photochemical formation and reversible base-induced cleavage of a phosphagallene

“…15–17 Just recently, our group isolated phospha- and arsaalumenes Dip TerPn = AlCp* and Tip TerP = AlCp* ( Dip Ter = 2,6-(2,6-iPr 2 C 6 H 3 ) 2 –C 6 H 3 ; Tip Ter = 2,4,6-(2,46-iPr 3 C 6 H 3 ) 2 –C 6 H 3 ; Cp* = C 5 Me 5 ; Pn = P ( C ), As; Fig. 1) 18,19 by combining the pnictinidene transfer reagents Ar TerPn(PMe 3 ) 20 (Ar = Dip, Tip) with (Cp*Al) 4 at 80 °C. 21,22 The heavier analogs of phosphaalumenes, phosphagallenes, have also been realized synthetically just recently, utilizing phosphanyl- or gallaphosphaketenes in the reaction with ( Dip Nacnac)Ga ( Dip Nacnac = HC[C(Me)NDip] 2 ) facilitating CO cleavage and formation of [(S)P]–PGa( Dip Nacnac) ( A ; [(S)P] = (H n CNDip) 2 P; n = 1, 2) 23 or ( Dip Nacnac)GaP–Ga(Cl)( Dip Nacnac) ( B , Fig.…”