126833-53-2

Upstream product

• 4407-36-7 (2E)-3-phenyl-2-propen-1-ol 
• 108-28-1 protoanemonin 
• 115062-59-4 3-phenyl-4-pentynoic acid 
• 126833-41-8 2,5-Bis-ethoxycarbonyl-3-oxo-4-phenyl-hexanedioic acid diethyl ester 
• 126833-45-2 3-Oxo-4-phenyl-hexanedioic acid 
• 5703-57-1 3-phenylpent-4-enoic acid 

Relevant academic research and scientific papers

A highly active diradical cobalt(iii) catalyst for the cycloisomerization of alkynoic acids

The first cobalt-catalysed cycloisomerisation of alkynoic acids is reported, thanks to the design of a well-defined diradical cobalt(iii) catalyst, in the absence of any additives. The high efficiency, regioselectivity and chemoselectivity are comparable to those of noble metal-based systems. The unique reactivity might be attributed to second coordination sphere effects.

Access to enantioenriched α-amino esters via rhodium-catalyzed 1,4-addition/enantioselective protonation

Conjugate addition of potassium trifluoro(organo)borates 2 to dehydroalanine derivatives 1, mediated by a chiral rhodium catalyst and in situ enantioselective protonation, afforded straightforward access to a variety of protected α-amino esters 3 with high yields and enantiomeric excesses up to 95%. Among the tested chiral ligands and proton sources, Binap, in combination with guaiacol (2-methoxyphenol), an inexpensive and nontoxic phenol, afforded the highest asymmetric inductions. Organostannanes have also shown to participate in this reaction. By a fine-tuning of the ester moiety, and using Difluorophos as chiral ligand, increased levels of enantioselectivity, generally close to 95%, were achieved. Deuterium labeling experiments revealed, and DFT calculation supported, an unusual mechanism involving a hydride transfer from the amido substituent to the α carbon explaining the high levels of enantioselectivity attained in controlling this α chiral center.

THE FIELD OF (TRIHALOGENOMETHYL)CARBINOLS. V. SYNTHESIS OF FUNCTIONALLY SUBSTITUTED 3- AND 4-PENTEN-4-OLIDES

The 1,1-dichloro-2-arylethylene oxides generated from arylz9trichloromethyl)carbinols in the potassium hydroxide-DMFA medium react with the carbanions of malonic and acetoacetic esters, forming diethyl 2,5-diethoxycarbonyl- and 2,5-diacetyl-4-aryl-3oxoadi

Synthesis of 4-Penten-4-olides (γ-Methylene-γ-butyrolactones) via 4-Pentenoic Acids

4-Penten-4-olides (γ-Methylene-γ-butyrolactones) 7 are easily accessible starting from allylic alcohols 1, which on ortho ester Claisen rearrangement and hydrolytic work-up furnish 4-pentenoic acids 5.The latter on iodolactonization and hydrogen iodide elimination by means of 1,8-diazabicycloundec-7-ene (DBU) furnish 7, in good over-all yield and with variable substitution patterns. - Iodolactonization under kinetic control shows moderate 1,2- or 1,3-asymmetric induction (3:1 and ca. 2:1, respectively).The composition of the iodolactone mixtures 6 as well as the individual relative configurations are deduced from 1H and 13C NMR data. - Similary, the spirobipentenolide 13 is obtained starting from diethyl diallylmalonate (9) via 11 resulting from ester iodocyclization.