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• 18531-94-7 (R)-1,1'-Bi-2-naphthol 
• 676567-87-6 bis(S,S)-[1-(2-methoxy-phenyl)-ethyl]-amine 
• 18531-99-2 (S)-[1,1']-binaphthalenyl-2,2'-diol 
• 280107-26-8 bis-[(R)-1-(2-methoxyphenyl)ethyl]amine 
• 40023-74-3 (S)-1-(2-methoxyphenyl)ethanamine 
• 579-74-8 2-Methoxyacetophenone 
• 602-09-5 1,1'-bi-2-naphthol 

Relevant academic research and scientific papers

Enantioselective Allylation of Alkenyl Boronates Promotes a 1,2-Metalate Rearrangement with 1,3-Diastereocontrol

Alkenyl boronates add to Ir(π-allyl) intermediates with high enantioselectivity. A 1,2-metalate shift forms a second C-C bond and sets a 1,3-stereochemical relationship. The three-component coupling provides tertiary boronic esters that can undergo multiple additional functionalizations. An extension to trisubstituted olefins sets three contiguous stereocenters.

Chagosensine: A Riddle Wrapped in a Mystery Inside an Enigma

The marine macrolide chagosensine is supposedly distinguished by a (Z,Z)-configured 1,3-chlorodiene contained within a highly strained 16-membered lactone ring, which also incorporates two trans-2,5-disubstituted tetrahydrofuran (THF) rings; this array is unique. After our initial synthesis campaign had shown that the originally proposed structure is incorrect, the published data set was critically revisited to identify potential mis-assignments. The "northern" THF ring and the anti-configured diol in the "southern" sector both seemed to be sites of concern, thus making it plausible that a panel of eight diastereomeric chagosensine-like compounds would allow the puzzle to be solved. To meet the challenge, the preparation of the required building blocks was optimized, and a convergent strategy for their assembly was developed. A key role was played by the cobalt-catalyzed oxidative cyclization of alken-5-ol derivatives ("Mukaiyama cyclization"), which is shown to be exquisitely chemoselective for terminal alkenes, leaving even terminal alkynes (and other sites of unsaturation) untouched. Likewise, a palladium-catalyzed alkyne alkoxycarbonylation reaction with formation of an α-methylene-?-lactone proved instrumental, which had not found application in natural product synthesis before. Further enabling steps were a nickel-catalyzed "Tamaru-type" homocrotylation, stereodivergent aldehyde homologations, radical hydroindation, and palladium-catalyzed alkyne-1,2-bis-stannation. The different building blocks were assembled in a serial fashion to give the idiosyncratic chlorodienes by an unprecedented site-selective Stille coupling followed by copper-mediated tin/chlorine exchange. The macrolactones were closed under forcing Yamaguchi conditions, and the resulting products were elaborated into the targeted compound library. Yet, only one of the eight diastereomers turned out to be stable in the solvent mixture that had been used to analyze the natural product; all other isomers were prone to ring opening and/or ring expansion. In addition to this stability issue, our self-consistent data set suggests that chagosensine has almost certainly little to do with the structure originally proposed by the isolation team.

Copper-catalyzed asymmetric conjugate addition of trialkylaluminium reagents to trisubstituted enones: Construction of chiral quaternary centers

Me3Al, Et1Al, and vinylalane species undergo enantioselective conjugate addition to a wide range of 2- or 3-substituted enones (cyclopent-2enones, cyclohex-2-enones, 3-methyl cyclohept-2-enone) in the presence of catalytic amount of copper salt (copper thiophene carboxylate, [Cu(CH3-CN)4]BF4 or [CuOTf]2· C6H6) and tropos-phosphoramidite-based ligand. Thus, chiral quaternary centers can be built, with up to 98% ee after rigorous optimization of experimental conditions. It was shown that the main important parameter was the order of the introduction of the reagents. Then, the generated enantioenriched aluminium enolates and the chiral conjugate adducts were functionalized and used for subsequent reactions.

Enantioselective copper-catalyzed conjugate addition to trisubstituted cyclohexenones: Construction of stereogenic quaternary centers

Trimethyl- and triethylaluminum undergo enantioselective conjugate addition to 3-and 2-substituted cyclohexenones in the presence of catalytic amounts of a Cu salt and a phosphoramidite ligand L* (see scheme). Thus, chiral quaternary centers can be built with up to 96.6% ee. Functionalized enones lead to bicyclic structures by a subsequent aldol reaction.

A highly effective phosphoramidite ligand for asymmetric allylic substitution

Very high enantioselectivity has been achieved both in the copper-catalyzed alkylation of allylic substrates by Grignard and organozinc reagents and in the iridium-catalyzed animation of cinnamyl carbonate by employing a very efficient phosphoramidite ligand (see scheme).