69610-04-4

Upstream product

• 887255-42-7 N-(1-formyl-2,2-dimethyl-propyl)-4-methyl-benzenesulfonamide 
• 20859-02-3 L-tert-Leucine 
• 98-59-9 p-toluenesulfonyl chloride 

Downstream Products

• 1226797-61-0 (S)-(+)-methyl 3,3-dimethyl-2-(p-toluenesulfonyl)aminobutyrate 
• 136579-62-9 (S)-3-tosyl-4-t-butyl-1,3,2-oxazaborolidin-5-one 
• 866458-31-3 (S)-3,3-Dimethyl-2-(toluene-4-sulfonylamino)-butyryl chloride 

Relevant academic research and scientific papers

Branch-Selective Addition of Unactivated Olefins into Imines and Aldehydes

Radical hydrofunctionalization occurs with ease using metal-hydride hydrogen atom transfer (MHAT) catalysis to couple alkenes and competent radicalophilic electrophiles. Traditional two-electron electrophiles have remained unreactive. Herein we report the reductive coupling of electronically unbiased olefins with imines and aldehydes. Iron catalysis allows addition of alkyl-substituted olefins into imines through the intermediacy of free radicals, whereas a combination of catalytic Co(Salt-Bu,t-Bu) and chromium salts enables a branch-selective coupling of olefins and aldehydes through the formation of a putative alkyl chromium intermediate.

Oxazoline derivatives tagged with tosylated amino acids as recyclable organocatalysts for enantioselective allylation of aldehydes

A series of amino acid-based oxazoline compounds have been prepared and successfully applied to the enantioselective allylation reaction of aldehydes. The fine-tuning of the structure of the oxazolines led to (S,S)-4 as an efficient organocatalyst which gave homoallyl alcohols in good yield (up to 90%) and excellent ee (up to 99%) for a wide range of substrates including aromatic, hetero-aromatic and α,β-unsaturated aldehydes. The chiral organocatalyst was synthesized in three easy steps with an overall 88% yield and successfully recycled for up to three cycles. On the basis of the experimental observations and NMR studies, a probable mechanism was proposed for this reaction.

Oxazoline-based organocatalyst for enantioselective strecker reactions: A protocol for the synthesis of levamisole

A chiral oxazoline-based or-ganocatalyst has been found to efficiently catalyze asymmetric Strecker reactions of various aromatic and aliphatic N-benzhydrylimines with trime-thylsilyl cyanide (TMSCN) as a cyanide source at -20°C to give α-aminoni-triles in high yield (96%) with excellent chiral induction (up to 98% ee). DFT calculations have been performed to rationalize the enantioselective formation of the product with the organo-catalyst in these reactions. The organo-catalyst has been characterized by single-crystal X-ray diffraction analysis, as well as by other analytical methods. This protocol has been extended to the synthesis of the pharmaceutically important drug molecule levamisole in high yield and with high enantioselectivity.

Asymmetric synthesis of N-tosyl amino acids from N-sulfinyl α-amino-1,3-dithioketals

Hydrolysis of diastereomerically pure N-sulfinyl α-amino-1,3- dithianes with 1,3-dibromo-5,5-dimethylhydantoin gives N-tosyl α-amino aldehydes which when subjected to a Pinnick-type oxidation gave N-tosyl α-amino acids without epimerization.

Amino acid-derived hydroxamic acids as chiral ligands in the vanadium catalysed epoxidation

New sulfonamide-derived hydroxamic acids 7-11 have been developed as chiral ligands for the V-catalysed asymmetric epoxidation, showing high reactivity at subzero temperatures and moderate to good enantioselectivity. The strong accelerating effect exhibited by the ligands of this type can be attributed to the sulfonamide functionality. A range of cinnamyl type allylic alcohols were epoxidised with up to 74% ee. The Royal Society of Chemistry 2005.