Unprecedented nucleophilic addition of organolithiums to aromatic aldehydes and ketones by complexation with aluminum tris(2,6-diphenylphenoxide).

Highly selective aluminium-catalysed intramolecular Prins reaction for l-menthol synthesis

“…Hence, a variety of methods has been reported for the diastereoselective cyclisation of citronellal to isopulegol. 11-14 For instance, tris(2,6-diphenylphenoxy)aluminium complex (ATPH, 4a), 14 which was prepared from triethylaluminium and 2,6-diphenylphenol (5a), has been used to carry out the Prins reaction of citronellal with a diastereoselectivity larger than 99% and 94% selectivity of 2 at 0 C. 11 However, 4a shows the excellent performance in a narrow temperature range. 4a In addition, various other aluminium complexes have been recently proposed as only catalysts that afford (5R)isopulegols with a high diastereoselectivity.…”

“…a Determined by gas chromatography (GC) analysis. When the substituents on citronellal were larger than a methyl group (13, 15, and 17), ACPP provided the corresponding products (14,16, and 18) with lower diastereoselectivity (entries 5-7). c Reacted at 0-5 C. d Et 3 Al (2 mol%) and 5b (6.2 mol%) were used and reacted for 4 h. e Ethyl glyoxylate (8.4 mol%) were used.…”

Stereoselective Dearomatizing Addition of Nucleophiles to Uncomplexed Benzene Rings: A Route to Carbocyclic Sugar Analogues

“…Current solutions to the problem adding nucleophiles stereoselectively addition of nucleophiles to simple substituted phenyl rings involve stoichiometric coordination to Cr, Mn, or Os 2a–e. Racemic dearomatized products may also be obtained from addition reactions to hindered benzamides2f,g or to carbonyl compounds coordinated to aluminum tris(2,6‐diphenylphenoxide) (ATPH) 2h–j…”

Synthetic Uses of Phenols

“…Aluminum tris(2,6-diphenylphenoxide) (ATPH) gives mostly 1,4-adducts even from unsaturated aldehydes (equation 59) 229 . These aluminum reagents were used in several selective syntheses which otherwise could not be conducted, such as 1,6-addition to acetophenone 230,231 , enolate formation from unsaturated aldehydes and aldol reaction at the remotest nuleophilic center 232 and selective alkylation of hindered aldehydes in the presence of less hindered aldehydes and ketones 233 . Use of appropriate phenoxides controls the double bond stereochemistry in the Claisen rearrangement of allyl vinyl ethers (equation 60) 234 , which was extended to asymmetric synthesis using a binaphthyl derivative ATBN-F (equation 61) 235 .…”