Iron‐Catalyzed Dehydropolymerization: A Convenient Route to Poly(phosphinoboranes) with Molecular‐Weight Control

Abstract

The catalyst loading is the key to control the molecular weight of the polymer in the iron-catalyzed dehydropolymerization of phosphine-borane adducts. Studies showed that the reaction proceeds through a chain-growth coordination-insertion mechanism.

Mechanism, reactivity, and regioselectivity in rhodium-catalyzed asymmetric ring-opening reactions of oxabicyclic alkenes: a DFT Investigation

“…The M06-2X functional2021 was used for the gas-phase geometry optimization of all species, which was demonstrated to be suitable for studying transition metal catalysis2223. The LANL2DZ basis set24 was employed for Rh and Fe, and the 6–31 G(d) basis set was used for other atoms (GEN1).…”

Coordination of Boron‐centered Lewis Acids by organo‐substituted Phosphanylboranes

“…We have shown that the reactions of the monomeric phosphanylboranes 1a and 1b with the main group Lewis acids BH 3 and BBr 3 lead to the compounds 2a-3b. The secondary and tertiary phosphines 1a and 1b behave as classical Lewis bases and coordinate to BX 3 (X = H, Br) as terminal groups.…”

“…E.g., it was shown that the poly(phosphinoborane) [RHP-BH 2 ] n (R = p-CF 3 C 6 H 4 ) can be used as an electron beam resist for lithographic applications. [1,4] The parent poly(phosphinoborane) [H 2 P-BH 2 ] n was prepared for the first time via B(C 6 F 5 ) 3 -catalyzed dehydrocoupling of H 3 P·BH 3 . A mixture of oligomers and low molar mass polymers (M n Ͻ 2000 g·mol -1 ) was obtained, which showed high sensitivity and decomposed under ambient conditions.…”

“…[9] These compounds can be viewed as donor-stabilized monomers of poly(phosphinoboranes) and thus are potential candidates for polymerization reactions. A mild thermolysis triggers the elimination of NMe 3 . The absence of the Lewis base leads to a lack of electronic stabilization (lone-pair at phosphorus together with a vacant p orbital at boron) resulting in a head-to-tail polymerization or oligomerization, respectively.…”

Spontaneous dehydrocoupling in peri-substituted phosphine–borane adducts

“…6,[9][10][11] In particular, amine-borane adducts have attracted considerable interest as potential hydrogen storage molecules. 15,16 In 1999 the Manners' group pioneered the use of transition metal catalysts in the synthesis of poly(phosphinoboranes) [17][18][19][20] and more recently B(C 6 F 5 ) 3 has been used as a metal-free dehydrocoupling catalyst. 11,14 Dehydrocoupling of phosphine-boranes to form poly(phosphinoboranes) was first reported in the 1950s.…”