Arylzinc Alkoxides:  [ArZnOCHP ]₂ and Ar₂Zn₃(OCHP )₄ When Ar = C₆H₅, p-CF₃C₆H₄, 2,4,6-Me₃C₆H₂, and C₆F₅

Abstract

From the reactions between diarylzinc compounds (Ar2Zn) and the alcohol (Pr(i)2CHOH) in toluene, the compounds [ArZn(OCHPr(i)2)]2 (Ar = C6H5, C6F5, p-CF3C6H4, and 2,4,6-Me3C6H2) have been isolated and shown to exist in equilibra with the trinuclear complexes Ar2Zn3(OCHPr(i)2)4 and Ar2Zn when Ar = C6H5, C6F5, and p-CF3C6H4. The trinuclear complexes have also been prepared from reactions of the Ar2Zn compounds with the alcohol, which reveals that the ease of Zn-C(aryl) bond cleavage is sensitive to the nature of the Ar group: C6H5 > 4-CF3C6H4 > C6F5. The molecular structures of Ar2Zn3(OCHPr(i)2)4 where Ar = p-CF3C6H4 and C6F5 and [ArZn(OCHPr(i)2)]2 where Ar = C6F5, p-CF3C6H4, and 2,4,6-Me3C6H2 are reported based on single-crystal X-ray diffraction studies. The X-ray structure of Zn(p-CF3C6H4)2 is also reported. The reactivity of these new compounds toward the polymerization of propylene oxide (PO) and the copolymerization of PO and CO2 have been investigated along with related reactions involving the partial hydrolysis of the Ar2Zn and R2Zn compounds, where R = t-Bu, n-Bu, and n-Oct. These results are compared with the previous studies employing Et2Zn as an organozinc precursor.

Zincocene and Dizincocene N‐Heterocyclic Carbene Complexes and Catalytic Hydrogenation of Imines and Ketones

“…These species are highly air and oxygen sensitive and appear to be pure by all spectroscopic methods. A similar phenomenon has been described earlier 22a…”

Conformational Isomerism in Monomeric, Low‐Coordinate Group 12 Complexes Stabilized by a Naphthyl‐Substituted m‐Terphenyl Ligand

“…The C‐Zn‐C angle in 1 [168.27(9)°] deviates significantly from linearity, unlike the essentially linear coordination displayed by the homoleptic Group 12 m ‐terphenyl complex [Hg(2,6‐Mes 2 C 6 H 3 ) 2 ],43 and the zinc diaryls [ZnMes 2 ]39, 40 and [Zn( p ‐CF 3 C 6 H 4 ) 2 ] 41. That said, the C‐Zn‐C angle in 1 is not too dissimilar from those exhibited in [ZnMes 2 *] (Mes*=2,4,6‐ t Bu 3 C 6 H 2 ; C‐Zn‐C 165.9(3)°)40 and [Zn{2,4,6‐(CF 3 ) 3 C 6 H 2 } 2 ] [C‐Zn‐C 170.0(1)°],37 zinc complexes, which also feature aryl ligands with substituents in the ortho ‐positions.…”

“…The Zn À C bond lengths in 1 (1.946(2) and 1.955(2) ) are almost identical, and are in the range exhibited by other monomeric diarylzinc complexes (1.926(4)-1.951 (5) ). [37][38][39][40][41][42] The C-Zn-C angle in 1 [168.27(9)8] deviates significantly from linearity, unlike the essentially linear coordination displayed by the homoleptic Group 12 m-terphenyl complex [Hg(2,6-Mes 2 C 6 H 3 ) 2 ], [43] and the zinc diaryls [ZnMes 2 ] [39,40] and [Zn(p-CF 3 C 6 H 4 ) 2 ]. [41] That said, the C-Zn-C angle in 1 is not too dissimilar from those exhibited in [ZnMes 2 *] (Mes* = 2,4,6-tBu 3 C 6 H 2 ; C-Zn-C 165.9(3)8) [40] and [Zn- [37] zinc complexes, which also feature aryl ligands with substituents in the ortho-positions.…”

Direct C(sp2)C(sp3) Cross‐Coupling of Diaryl Zinc Reagents with Benzylic, Primary, Secondary, and Tertiary Alkyl Halides

“…Thelack of cross-coupling using zincate 8 led us to target bona-fide examples of etherate-free diarylzinc reagents, af amily of compounds that are relatively scarce within the literature. [39,40] Dimesitylzinc had been generated previously in an etherate-free form from mesitylmagnesium bromide and ZnCl 2 in THF. [41] Pleasingly,the combination of dimesitylzinc with 2 in [D 6 ]benzene led to rapid cross-coupling to form 9ain high yield (82 %), with the rate of reaction not appreciably diminished for this sterically hindered diaryl zinc reagent (Scheme 1).…”