138407-35-9

Upstream product

• 108-05-4 vinyl acetate 
• 71697-18-2 1,2-propyleneglycol-1-triphenylmethyl ether 
• 76-83-5 trityl chloride 
• 108-22-5 Isopropenyl acetate 

Downstream Products

• 20263-26-7 (R)-1-triphenylmethylmethoxy-2-propanol 
• 4254-14-2 (2R)-propane-1,2-diol 

Relevant academic research and scientific papers

Immobilized lipase screening towards continuous-flow kinetic resolution of (±)-1,2-propanediol

Here, we report a flow chemistry approach for kinetic resolution of (±)-1,2-propanediol protected by trityl group using the packed-bed reactor filled with different immobilized enzymes. It was investigated the performance of 16 immobilized lipases, includ

Continuous-Flow Synthesis of (R)-Propylene Carbonate: An Important Intermediate in the Synthesis of Tenofovir

(R)-Propylene carbonate is an important intermediate in the synthesis of tenofovir pro-drugs such as tenofovir alafenamide fumarate (TAF) and tenofovir diisoproyl fumarate (TDF). Independent of the pro-drug type, tenofovir presents a chiral secondary hydroxy derivative, which can be obtained directly from (R)-propylene carbonate. Herein, we report our chemo-enzymatic continuous-flow strategy towards (R)-propylene carbonate starting from a very cheap and renewable raw material, glycerol. We were able to synthesize (R)-propylene carbonate in seven continuous-flow steps, starting from glycerol, in good-to-excellent yields (66–93 %) and excellent selectivity (E > 200).

Resolution of a racemic 1,2-diol using triphenylmethyl protection of the primary hydroxyl group and Mucor miehei lipase (Lipozyme) for the kinetic resolution

The triphenylmethyl group gives very simple access to the 1-protection of 1,2-diol as exemplified by racemic propane-1,2-diol. This group has, however, been shown to be incompatible with lipases commonly used for the resolution of alcohols. This turned out to be the case for Pseudomonas cepacia lipase, which we have used in our earlier work. Lipozyme, a Mucor miehei lipase, best known for 1,3-selectivity with glycerol is, however, shown to catalyze transacetylation onto the secondary hydroxyl group next to a triphenylmethoxy group. The transacetylation is completely enantioselective for the (R)-enantiomer giving a very simple method for the resolution of this type of 1,2-diol enantiomer.

Aminocyclopentadienyl Ruthenium Complexes as Racemization Catalysts for Dynamic Kinetic Resolution of Secondary Alcohols at Ambient Temperature

Aminocyclopentadienyl ruthenium complexes, which can be used as room-temperature racemization catalysts with lipases in the dynamic kinetic resolution (DKR) of secondary alcohols, were synthesized from cyclopenta-2,4-dienimines, Ru3(CO)12, and CHCl 3: [2,3,4,5-Ph4(η5-C 4CNHR)]Ru-(CO)2Cl (4: R = i-Pr; 5: R = n-Pr; 6: R = t-Bu), [2,5-Me2-3,4-Ph2(η5-C 4CNHR)]Ru(CO)2Cl (7: R = i-Pr; 8: R = Ph), and [2,3,4,5-Ph4(η5-C4CNHAr)]Ru(CO) 2Cl (9: Ar =p-NO2C6H4; 10: Ar = p-ClC6H4; 11: Ar = Ph; 12: Ar = p-OMeC6H 4; 13: Ar = p-NMe2C6H4). The tests in the racemization of (S)-4-phenyl-2-butanol showed that 7 is the most active catalyst, although the difference decreased in the DKR. Complex 4 was used in the DKR of various alcohols; at room temperature, not only simple alcohols but also functionalized ones such as allylic alcohols, alkynyl alcohols, diols, hydroxyl esters, and chlorohydrins were successfully transformed to chiral acetates. In mechanistic studies for the catalytic racemization, ruthenium hydride 14 appeared to be a key species. It was the major organometallic species in the racemization of (S)-1-phenylethanol with 4 and potassium tert-butoxide. In a separate experiment, (S)-1-phenylethanol was racemized catalytically by 14 in the presence of acetophenone.