Treatment of Naphthols with B(C6F5)3: Formation and Characterization of the Lewis Acid Adducts of Their Keto Isomers

Abstract

With the strong Lewis acid B(C(6)F(5))(3), the keto tautomers from a variety of naphthol derivatives are obtained (e.g. alpha-naphthol, see scheme). The adducts of the tautomers were characterized by X-ray structure analysis, and the first attempts at hydrozirconation of the adducts were made.

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“…For complex 2 , the AlO and BO bond lengths of 1.780(2) and 1.311(2) Å (Figure 2), respectively, are in the range of those in previously reported compounds 1. 6c…”

Pentafluorophenylboronic acid

“…Crystallographic studies on compounds which contain a similar (C 6 F 5 )BO 2 motif are limited to the cyclic pentauorophenylboronic acid ester of 2,3-dihydroxynaphthalene, (C 6 F 5 )BO 2 C 10 H 6 (Vagedes et al, 1999) and the metallocycle [ZrCp 2 {"-O 2 B(C 6 F 5 )}] 2 (Balkwill et al, 2002). The motif also appears in the borate anion of the salt [CpNi(C 6 H 6 )NiCp]-[B 3 O 3 (C 6 F 5 ) 5 ] (Priego et al, 2000), in which there are B atoms with both trigonal and tetrahedral geometry.…”

Formation of macrocyclic ring systems by carbonylation of trifunctional P/B/B frustrated Lewis pairs

“…Endergonic opening of the P···B linkage of 11b yields the reactive P/B/B intermediate 11open , which may undergo the typical 1,1-P/B FLP addition reaction to carbon monoxide. 35 , 36 Carbonyl activation by the remaining pendent –B(C 6 F 5 ) 2 functionality 70 , 71 via 16A might initiate the kinetically facile and thermodynamically feasible formation of the CO insertion product 32 16B . Isomerization forms the P/B Lewis pair.…”