Asymmetric synthesis of axially chiral 1,1′-biphenyl-2-carboxylates via nucleophilic aromatic substitution on 2-menthoxybenzoates by aryl Grignard reagents

Atroposelective Synthesis of Axially Chiral Biaryl Compounds

“…In contrast to the formation of binaphthyls, the analogous preparation of biphenyls proved to be more difficult, with tri‐ ortho ‐substituted examples giving mainly modest atropoenantioselectivities 171. The reaction of 148 with ( R )‐ 149 to afford the tetra‐ ortho ‐substituted biphenyl ( M )‐ 150 did, however, proceed in high chemical yield and optical purity (Scheme ).…”

Direct Displacement of Alkoxy Groups of Vinylogous Esters by Grignard Reagents

“…5 Displacement of ortho -methoxy groups from extremely hindered benzoate esters was also demonstrated. 6 A more general synthetic strategy was realized by replacing carbonyl groups with oxazolines to serve as carboxylic acid equivalents that avoided any potential carbonyl addition. 7 This reaction was subsequently extended to naphthalenes, 8 rendered asymmetric with chiral oxazolines, 9 and used as a key bond construction in the assembly of natural products.…”

Axially Chiral 1,1'‐Binaphthyl‐2‐Carboxylic Acid (BINA‐Cox) as Ligands for Titanium‐Catalyzed Asymmetric Hydroalkoxylation

“…The Miyano synthesis of L1 involves a key S N Ar‐reaction of 1‐naphthylmagnesium bromide ( 9 ) with menthyl 1‐menthyloxy‐2‐napthoate ( 7 ; Scheme ), in which the etheric menthyloxy leaving group is responsible for induction, and the menthyl ester suppresses acyl substitution through shielding of the ester carbonyl . The methodology has been applied by other groups,, [16a], [16b], [16c], and we also got satisfactory results at small scale.…”