95033-75-3

Upstream product

• 33070-58-5 1,3,6,8-tetra-n-butylpyrimido<5,4-g>pteridine-2,4,5,7(1H,3H,6H,8H)-tetrone 10-oxide 
• 85-01-8 phenanthrene 
• 484-17-3 9-Phenanthrol 
• 95033-74-2 rac-10,10'-dihydroxy-9,9'-biphenanthryl 
• 4559-70-0 Diphenylphosphine oxide 

Downstream Products

• 190841-70-4 Dimethyl-thiocarbamic acid O-(10'-dimethylthiocarbamoyloxy-[9,9']biphenanthrenyl-10-yl) ester 
• 202-72-2 diphenanthro[9,10-b:9',10'-d]thiophene 
• 924904-18-7 (+)-(S)-10,10'-dimethoxy-9,9'-biphenanthryl 

Relevant academic research and scientific papers

Enantiodivergent Kinetic Resolution of 1,1′-Biaryl-2,2′-Diols and Amino Alcohols by Dipeptide-Phosphonium Salt Catalysis Inspired by the Atherton–Todd Reaction

A highly enantiodivergent organocatalytic method is disclosed for the synthesis of atropisomeric biaryls via kinetic resolution inspired by a dipeptide-phosphonium salt-catalyzed Atherton–Todd (A-T) reaction. This flexible approach led to both R- and S-enantiomers by fine-tuning of bifunctional phosphonium with excellent selectivity factors (s) of up to 1057 and 525, respectively. The potential of newly synthesized O-phosphorylated biaryl diols was illustrated by the synthesis of axially chiral organophosphorus compounds. Mechanistic investigations suggest that the bifunctional phosphonium halide catalyst differentiates between the in-situ-generated P-species in the A-T process, mainly involving phosphoryl chloride and phosphoric anhydride, thus leading to highly enantiodivergent O-phosphorylation reactions. Furthermore hydrogen bonding interactions between the catalysts and phosphorus molecules were crucial in asymmetric induction.

Isothiourea-Catalysed Regioselective Acylative Kinetic Resolution of Axially Chiral Biaryl Diols

An operationally simple isothiourea-catalysed acylative kinetic resolution of unprotected 1,1′-biaryl-2,2′-diol derivatives has been developed to allow access to axially chiral compounds in highly enantioenriched form (s values up to 190). Investigation of the reaction scope and limitations provided three key observations: i) the diol motif of the substrate was essential for good conversion and high s values; ii) the use of an α,α-disubstituted mixed anhydride (2,2-diphenylacetic pivalic anhydride) was critical to minimize diacylation and give high selectivity; iii) the presence of substituents in the 3,3′-positions of the diol hindered effective acylation. This final observation was exploited for the highly regioselective acylative kinetic resolution of unsymmetrical biaryl diol substrates bearing a single 3-substituent. Based on the key observations identified, acylation transition state models have been proposed to explain the atropselectivity of this kinetic resolution.