123366-90-5

Upstream product

• 46687-57-4 (S)-3-phenyl-2-(1H-pyrrol-1-yl)propanoic acid 
• 696-59-3 cis,trans-2,5-dimethoxytetrahydrofuran 
• 3182-95-4 L-Phenylalaninol 
• 116763-08-7 methyl (S)-3-phenyl-2-(1H-pyrrol-1-yl)propanoate 

Downstream Products

• 3182-95-4 L-Phenylalaninol 

Relevant academic research and scientific papers

Pyrrole-Protected β-Aminoalkylzinc Reagents for the Enantioselective Synthesis of Amino-Derivatives

Chiral β-aminoalkylzinc halides were prepared starting from optically pure commercial β-amino-alcohols. These amino-alcohols were converted to the corresponding N-pyrrolyl-protected alkyl iodides which undergo a zinc insertion in the presence of LiCl (THF, 25 °C, 10–90 min). Subsequent Negishi cross-coupling or acylation reactions with acid chlorides produced amino-derivatives with retention of chirality. Diastereoselective CBS-reductions of some prepared N-pyrrolyl-ketones provided 1,3-subsituted N-pyrrolyl-alcohols with high diastereoselectivity. Additionally, a deprotection procedure involving an ozonolysis allowed the conversion of the pyrrole-ring into a formamide without loss of optical purity.

Catalytic Hydrogenation of N-protected α-Amino Acids Using Ruthenium Complexes with Monodentate Phosphine Ligands

A ruthenium complex with a monodentate phosphine ligand was used to catalytically hydrogenate N-protected α-amino acids under essential retention of the configuration of their α-chiral centers. Among the ligands tested for this hydrogenation, which proceeds at a relatively low temperature, tris(para-fluorophenyl)phosphine exhibited the best performance. In comparison, electron-rich monodentate, bidentate, and tridentate phosphines were far less effective. The precatalyst Ru(OAc)2[(p-FC6H4)3P]2 was synthesized and isolated, and its structure was determined by a single-crystal X-ray diffraction analysis. N-protected α-amino acids with neutral alkyl side chains, including polar functional groups such as sulfides, indoles, ethers, phenols, pyrroles, and arenes, are compatible with the applied hydrogenation conditions, affording the corresponding optically active 2-substituted-2-(1H-pyrrol-1-yl)ethan-1-ol (2-amino ethanol) derivatives in moderate to high yield. (Figure presented.).

METHOD FOR PRODUCING OPTICALLY ACTIVE CARBOXYLIC ACID ESTER

Provided is a method for producing an optically active carboxylic acid ester at a high yield and with high enantioselectivity using dynamic kinetic resolution, said optically active carboxylic acid ester having an α-nitrogen substituent. This method for producing an optically active carboxylic acid ester includes a step in which racemic carboxylic acid represented by formula (a) and a specific alcohol or phenol derivative are reacted in a polar solvent having a dipole moment of at least 3.5 in the presence of an acid anhydride and an asymmetric catalyst, one enantiomer of the racemic carboxylic acid is selectively esterified, and the other enantiomer is racemized. In formula (a), Ra1 represents a nitrogen-containing heteroaromatic ring group bonded to an assymetric carbon via a nitrogen atom constituting a ring, and Ra2 is an organic group.

Nonenzymatic, enantioconvergent dynamic kinetic resolution (DKR) of racemic 2-(1H-pyrrol-1-yl)alkanoic acids as α-amino acid equivalents

We report an effective dynamic kinetic resolution (DKR) system of racemic 2-(1H-pyrrol-1-yl)alkanoic acids, which consists of a rapid racemization step via an activating substrate and an enantio-discriminating step via catalytic esterification. The combination of pivalic anhydride as an activating agent, bis(α-naphthyl)methanol as an achiral alcohol, (R)-BTM as a chiral acyl-transfer catalyst, and Hunig's base converted racemic 2-(1H-pyrrol-1-yl)alkanoic acids to the corresponding chiral carboxylates, which can be transformed into chiral α-amino acid derivatives with maintained high enantiopurity.

Synthesis and Stereoselective Reactions of 2-(Pyrrol-1-yl)alkanals and 2-(pyrrol-1-yl)alkan-1-ones

2-(2,5-Dimethylpyrrol-1-yl)alkanals, 2-(pyrrol-1-yl)alkanals, and 2-(2,5-dimethylpyrrol-1-yl)alkan-1-ones were prepared.The reactions of these compounds with Grignard and hydride reagents proceeded stereoselectively to give the corresponding 2-(pyrrol-1-yl)alcohols, which were converted into 2-aminoalcohols, such as norephedrine and ephedrine, by cleavage of the pyrrole ring.