54321-15-2

Upstream product

• 13490-71-6 (S)-(+)-α-tert-butylphenylacetic acid 
• 865363-47-9 (S)-3,3-Dimethyl-2-phenyl-butyric acid 2,2-diphenyl-vinyl ester 
• 4513-94-4 1H-pyrrole-2-carbonitrile 
• 57768-77-1 phenyl tert-butyl ketene 
• 5676-29-9 (3,3-dimethylbut-1-en-2-yl)benzene 

Relevant academic research and scientific papers

Filling the gaps in the challenging asymmetric hydroboration of 1,1-disubstituted alkenes with simple phosphite-based phosphinooxazoline iridium catalysts

We have identified a readily accessible phosphinooxazoline-based phosphite-oxazoline catalytic system, (S)-4-isopropyl-2-{2-[(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite]-phenyl}-2-oxazoline (L1a), that can hydroborate a range of 1,1-disubstituted aryl olefins with high enantioselectivity (up to 94%), excellent yields and perfect regioselectivity. The new phosphite-oxazoline ligands efficiently hydroborate a broader range of olefins than previous phosphinooxazoline ligands. In particular, a wide range of α-tert-butylstyrenes can be hydroborated that bear aryl substituents with different electronic and steric properties, which complements previous results with N-heterocyclic copper catalysts, the only other system reported to date that has achieved these reactions.

Catalytic asymmetric couplings of ketenes with aldehydes to generate enol esters

(Chemical Equation Presented) With a little help from the ferrocenyl catalyst ((-)-1), a wide array of α-arylalkanoic acid derivatives can be produced from the catalytic asymmetric coupling of ketenes with aldehydes (see scheme). The enol esters are readily transformed into other useful families of compounds such as carboxylic acids and alcohols.

Stereochemistry of Aliphatic Carbocations, 15. Rearrangements in 2-Arylalkyl Systems

Phenyl shifts from secondary to primary carbon proceed with virtually complete inversion at the migration origin, regardless whether they are induced by solvolysis of the aryl sulfonate 25 or by deamination of the amines 12, 17, 26, and 43.Sequential rearrangements (Ph, CH3 and Ph, H) are likewise stereo- and regiospecific.These results strongly support the intervention of phenonium ions.In contrast, the competitive alkyl shifts (deamination only) from benzylic to primary carbon produce but a small excess of inversion (Me 27percent, Et 13percent, iPr 20percent, tBu 3percent).Obviously, benzyl cations are the predominant intermediates.