Tris(5,6,7,8-tetrafluoronaphthalen-2-yl)borane, a Partially Fluorinated Boron Lewis Acid with Fluorination Distal to the Boron Atom

Abstract

Typical congeners of the boron Lewis acid tris(pentafluorophenyl)borane, B(C 6 F 5 ) 3 , are fluorinated at the aryl groups directly attached to the boron atom. The chemistry of related electron-deficient boranes with fluorination distal to the Lewis acidic center is largely unexplored. The preparation and characterization of tris(5,6,7,8tetrafluoronaphthalen-2-yl)borane are reported. It serves as a model system that provides sites for further substitution at C-1 and C-3 of the naphthalen-2-yl units. A Gutmann− Beckett analysis of its Lewis acidity revealed that, despite remote fluorination, it is as Lewis acidic as B(C 6 F 5 ) 3 . The new Lewis acid performs equally well in CO and CN reduction as well as dehydrogenative Si−O coupling involving Si−H bond activation. Adducts with water and a phosphine oxide are crystallographically characterized.

Synthetic Method for 2,2'‐Disubstituted Fluorinated Binaphthyl Derivatives and Application as Chiral Source in Design of Chiral Mono‐Phosphoric Acid Catalyst

“…In this context, we chose Mg(TMP) 2 as base . We expected that since Mg(TMP) 2 has been known as a thermally stable base, its magnesiation strategy for fluoroaryls may open up to the reactions of thermally robust fluoroaryl amido Grignard reagents with a variety of electrophiles …”

“…41,42,[47][48][49][50] We expected that since Mg(TMP) 2 has been known as a thermally stable base, its magnesiation strategy for fluoroaryls may open up to the reactions of thermally robust fluoroaryl amido Grignard reagents with a variety of electrophiles. 51,52 At first, we examined the magnesiation of 1 via the treatment of Mg(TMP) 2 in formylation reaction using N,Ndimethylformamide (DMF) as an electrophile (Scheme 1). We found that the magnesiation of 1 readily proceeded at 0°C followed by the reaction with DMF to give the Scheme 1.…”

Synthesis and Molecular Properties of Partially Fluorinated DNTTs**

“…The analytical data were in agreement with the literature. [38] R f = 0.32 (n-pentane). BBr 3 (1 m in CH 2 Cl 2 , 4.31 mL, 4.31 mmol, 4.00 eq) was added to a solution of 1,2,3,4-tetrafluoro-6-methoxy-naphthalene (248 mg, 1.08 mmol, 1.00 eq) in CH 2 Cl 2 (15 mL) at 0°C.…”

“…The analytical data were in agreement with the literature. [38] R f = 0.52 (n-pentane/EtOAc 5 : 1). 1 Tf 2 O (1.60 mL, 9.50 mmol, 1.30 eq) was added dropwise to a solution of 5,6,7,8-tetrafluoronaphthalen-2-ol (1.58 g, 7.31 mmol, 1.00 eq) and pyridine (0.89 mL, 11.0 mmol, 1.50 eq) in CH 2 Cl 2 (28 mL) at 0°C.…”

B(C6F5)3‐katalysierte Hydrierung von Oximethern ohne Spaltung der N‐O‐Bindung

“…5). [16] [17] zum freien Oxim (2 a!1 a, nicht gezeigt) die Gewinnung von 2 a. Die Verwendung von Tetra-n-butylammoniumfluorid (TBAF) in THF ergab gleichermaßen eine komplexe Reaktionsmischung.…”