The Bis(allyl)bismuth Cation: A Reagent for Direct Allyl Transfer by Lewis Acid Activation and Controlled Radical Polymerization

Abstract

A positive effect: the bis(allyl)bismuth cation in [Bi(C(3)H(5))(2)(thf)(2)][B(C(6)H(3)Cl(2))(4)] is superior to neutral tris(allyl)bismuth in the additive-free allylation of unsaturated C-heteroatom functionalities and the controlled living radical polymerization of activated olefins.

Cationic Bismuth Amides: Accessibility, Structure, and Reactivity

“…Deviations from an ideal octahedral coordination geometry are due to the bridging coordination mode of two amido groups and to the weak bonding of one THF ligand (see below). In contrast to other cationic bismuth compounds with monodentate ligands, the bismuth‐centered lone pair in 4 is not stereochemically active . The two crystallographically distinct Bi−N distances that involve the bridging amido groups are identical within limits of error (Bi1−N1/N1′, 2.34 Å) and elongated compared to terminal Bi1‐N2 bonds (2.12 Å).…”

“…This makes them attractive targets for applications in stoichiometric group transfer reactions and catalysis. Catalytic transformations that have been realized to date include the allylation of aldehydes, diastereoselective aldol condensations, diastereoselective Mannich reactions, and the polymerization of activated olefins …”

Synthesis and Structure of Bis- and Tris-Benzyl Bismuth Complexes

“…22 Each benzyl ligand in 1 is coordinated in an η 1 -bonding mode with Bi−C−C(ipso) bond angles of 105.0(3)°and 107.9(3)°. 13 The 2.299(4) and 2.340(4) Å Bi−C(benzyl) bond lengths are in the range observed for Bi−C(alkyl) single bonds: 2.23(2)-2.29(2) Å, BiMe 3 ; 9 2.200(9)-2.267(7) Å, Bi( i Pr) 3 8 The distances in 1 are also consistent with other main group metal benzyl bonds, e.g. Ph 3 Pb-(CH 2 Ph), 28 Sb(CH 2 Ph) 3 , 29 and Al(CH 2 Ph) 3 ·Et 2 O, 30 at 2.242(7), 2.175(3), and 1.986(6) Å, respectively, when the difference in metal size is taken into account.…”

“…8 In contrast, earlier studies have shown that although Bi(CH 2 Ph) 3 is air sensitive, 12 it has a melting point of 65°C 11 and begins to decompose thermally at 110°C. 12 Compound 1 shows no evidence of decomposition from prolonged exposure to light or vacuum.…”

Synthesis of Alkylbismuths by Regiodivergent Carbobismuthination of Simple Alkenes

“…Organobismuth compounds have recently attracted much attention because they show remarkably characteristic reactivities including highly effective initiation of living radical polymerization,1 para CH activation of phenol derivatives,2 direct allyl transfer to carbonyls,1c α‐phenylation of carbonyls,3 and other traditional reactions such as cross‐coupling and addition reactions to carbonyl compounds 4. However, most of the practical syntheses of organobismuths involve transmetalation between a bismuth halide and an organometallic compound, which has limited the number of compatible functional groups and constricted the development of organobismuth chemistry 4.…”