An expedient route to some monoalkyl ethers of enantiomerically pure bi-β-naphthol

Rhodium/tris-binaphthyl chiral monophosphite complexes: Efficient catalysts for the hydroformylation of disubstituted aryl olefins

“…To a stirred solution of 1 (5.0 g, 17 mmol), PPh 3 (4.5 g, 17 mmol) and the desired alcohol 2aed (20 mmol) in dry THF (100 mL), diethyl azodicarboxylate (DEAD) (40% in toluene, 7.5 mL, 17 mmol) was dropwise added at 0 C. After 48 h at room temperature, the solvent was evaporated and the mono-alkyl ethers 3aed were isolated by silica gel column chromatography, using dichloromethane/nhexane (1:1) as eluent, and the products were further purified by recrystallization from toluene/n-hexane. Spectroscopic data of 3aec were in good agreement with those previously reported [38] (Note: DEAD is highly toxic, so the appropriate safety procedures were taken for its manipulation. R: 5-11-20-36/37/38-48/20-63-65-67; S: 26-36/37-62).…”

The First Asymmetric Halogen/Metal‐Exchange Reaction: Desymmetrization of Alcohols with Enantiotopic Bromoarene Substituents

“…Alcohols 11 and 12 as well as aminoalcohol 14 and (S)-2,2'-dihydroxy-1,1'-binaphthalene [(S)-BINOL (17 a)] were purchased. Aminoalcohols 13 a, [17] 13 b, [18] 13 c, [19] 13 d, [20] 15 a, [21] 15 b, [22] 16 a, [23] and 16 b [24] were prepared according to literature procedures, and (S)-BINOL-monoethers 17 b [25,26] and 17 c, d as well. [26] NHC precursor 21 is an elaborated 2-amino-2'-hydroxy-1,1'-binaphthalene (NOBIN) and was obtained by our recently developed synthesis [27] in 55 % overall yield, avoiding the lengthier previous synthesis.…”

“…89 % yield [29] ). Monomethylation or -benzylation of binaphthol 18 a under Mitsunobu conditions [26] provided the new BINOL-derived ethers 18 b and 18 c, respectively, in 93 % yield in both cases.…”

“…HCl, D) and reprotection (MeOH, trifluoroacetic acid) steps (74 % yield [30] overall). Mitsunobu conditions [26] were again appropriate for effecting the monoalkylations leading to the triethers 19 b (86 %) and 19 c (77 %) selectively.…”

Chiral pesticides

“…39) A series of monoalkyl ethers of optically active BINOL has been synthesized using the Mitsunobu reaction. 40) Chiral BINOL derivatives are well-recognized chiral catalysts and auxiliaries for the production of various useful optically active compounds 41) and numerous asymmetric reactions have been developed using chiral BINOL derivatives as chiral templates. 42) Researchers have reported the preparation of a precursor (substituted dichlorocyclopropanecarboxylic acid chloride, R-(ϩ)-p-chlorophenethylamine) for the active substance carpropamid (23) (Fig.…”