144464-74-4

Upstream product

• 867-13-0 diethoxyphosphoryl-acetic acid ethyl ester 
• 121-97-1 4-Methoxypropiophenone 
• 55314-57-3 ethyl pent-2-ynoate 
• 5720-07-0 4-methoxyphenylboronic acid 
• 1099-45-2 ethyl (triphenylphosphoranylidene)acetate 

Downstream Products

• 7706-82-3 (Z)-3-(4-methoxyphenyl)-2-butenoic acid ethyl ester 
• 30219-43-3 cis-β-Aethyl-p-methoxyzimtsaeure 
• 1448857-12-2 (E)-3-(4-methoxyphenyl)-1-phenylpent-2-en-1-one 
• 30219-42-2 (E)-3-(4-methoxyphenyl)pent-2-enoic acid 

Relevant academic research and scientific papers

Highly Selective and Catalytic Generation of Acyclic Quaternary Carbon Stereocenters via Functionalization of 1,3-Dienes with CO2

The catalytic asymmetric functionalization of readily available 1,3-dienes is highly important, but current examples are mostly limited to the construction of tertiary chiral centers. The asymmetric generation of acyclic products containing all-carbon quaternary stereocenters from substituted 1,3-dienes represents a more challenging, but highly desirable, synthetic process for which there are very few examples. Herein, we report the highly selective copper-catalyzed generation of chiral all-carbon acyclic quaternary stereocenters via functionalization of 1,3-dienes with CO2. A variety of readily available 1,1-disubstituted 1,3-dienes, as well as a 1,3,5-triene, undergo reductive hydroxymethylation with high chemo-, regio-, E/Z-, and enantioselectivities. The reported method features good functional group tolerance, is readily scaled up to at least 5 mmol of starting diene, and generates chiral products that are useful building blocks for further derivatization. Systemic mechanistic investigations using density functional theory calculations were performed and provided the first theoretical investigation for an asymmetric transformation involving CO2. These computational results indicate that the 1,2-hydrocupration of 1,3-diene proceeds with high π-facial selectivity to generate an (S)-allylcopper intermediate, which further induces the chirality of the quaternary carbon center in the final product. The 1,4-addition of an internal allylcopper complex, which differs from previous reports involving terminal allylmetallic intermediates, to CO2 kinetically determines the E/Z- and regioselectivity. The rapid reduction of a copper carboxylate intermediate to the corresponding silyl-ether in the presence of Me(MeO)2SiH provides the exergonic impetus and leads to chemoselective hydroxymethylation rather than carboxylation. These results provide new insights for guiding further development of asymmetric C-C bond formations with CO2

Spatiotemporal Control of Pre-existing Alkene Geometry: A Bio-Inspired Route to 4-Trifluoromethyl-2H-chromenes

Routes to prepare C4-trifluoromethyl analogues of the 2H-chromene scaffold are scarce: this is particularly striking given the importance of fluorine in pharmaceutical development. To address this limitation, a facile strategy has been developed that is reliant on catalytic, geometric isomerization of easily accessible allylic alcohols (up to >95:5) followed by intramolecular cyclization via Pd catalysis (up to 96%). This concise biomimetic approach emulates the photoisomerization/cyclization cascade inherent to phenylpropanoid biosynthesis.

A Bio-Inspired, Catalytic e → Z Isomerization of Activated Olefins

Herein, Natures flavin-mediated activation of complex (poly)enes has been translated to a small molecule paradigm culminating in a highly (Z)-selective, catalytic isomerization of activated olefins using (-)-riboflavin (up to 99:1 Z/E). In contrast to the prominent Z → E isomerization of the natural system, it was possible to invert the directionality of the isomerization (E → Z) by simultaneously truncating the retinal scaffold, and introducing a third olefin substituent to augment A1,3-strain upon isomerization. Consequently, conjugation is reduced in the product chromophore leading to a substrate/product combination with discrete photophysical signatures. The operationally simple isomerization protocol has been applied to a variety of enone-derived substrates and showcased in the preparation of the medically relevant 4-substituted coumarin scaffold. A correlation of sensitizer triplet energy (ET) and reaction efficiency, together with the study of additive effects and mechanistic probes, is consistent with a triplet energy transfer mechanism.

Effect of multinuclear copper/aluminum complexes in highly asymmetric conjugate addition of trimethylaluminum to acyclic enones

Al and friends: Asymmetric conjugate addition of Me3Al to β,β-disubstituted α,β-unsaturated ketones in the presence copper and L1 leads to a highly efficient construction of an all-carbon-substituted chiral quaternary center. This result is the first example of an asymmetric conjugate addition of Me3Al to acyclic enones to give a chiral quaternary carbon center with excellent yield and enantioselectivity under mild reaction conditions. Copyright

Remarkable reversal of stereoselectivity in Wittig-type olefinations of α-fluorinated alkyl aryl ketones

Remarkable reactivity and reversal of stereoselectivity in the Wittig-type olefinations of α-fluorinated alkyl aryl ketones were described. Stabilized Wittig and Horner-Emmons reagents with these ketones selectively afforded the olefinic products in the stereochemically opposite fashion to the non-fluorinated ketone cases. The Still's reagent further reversed the stereochemical outcome with the fluorinated ketones.