64252-49-9

Upstream product

• 57585-09-8 methyl 4-phenylpenta-2,3-dienoate 
• 16695-14-0 Malonic acid monomethyl ester 
• 34713-70-7 2-Phenylpropanal 
• 116-54-1 dichloroacetic acid methyl ester 
• 1067-74-9 Methyl diethylphosphonoacetate 
• 96-32-2 bromoacetic acid methyl ester 
• 60779-09-1 1-phenylethylmagnesium chloride 
• 18365-24-7 Triphenylstannanyl-acetic acid methyl ester 
• 21204-67-1 methyl (triphenylphosphoranylidene)acetate 
• 25145-43-1 2-phenylpropionyl chloride 
• 57585-21-4 4-phenylpenta-2,3-dienoic acid 
• 399551-33-8 methyl 2,3-epoxy-4-phenylpentanoate 
• 184377-59-1 E-2-carbomethoxyethenyl p-tolyl sulfoxide 

Downstream Products

• 20881-29-2 dihydro-α-norcurcumenic acid methylester 
• 1259027-52-5 (R)-(E)-2-(bis(4-(dimethylamino)phenyl)methyl)-4-phenylpent-3-enal 
• 1259027-51-4 (2E)-4-phenylpent-2-enal 
• 147189-58-0 4-methyl-4-phenylbut-2-enol 

Relevant academic research and scientific papers

Phosphetane oxides as redox cycling catalysts in the catalytic wittig reaction at room temperature

Recently, phosphorus redox cycling has gained significant importance for a number of transformations originally requiring the use of stoichiometric amounts of phosphorus reagents. While these methodologies have several benefits, high catalyst loadings (≥10 mol percent) and harsh reaction conditions (T ≥ 100 °C) often limit their versatility and applicability. Herein, we report differently substituted phosphetane oxides as efficient catalysts for the catalytic Wittig reaction. The phosphetane scaffold is easy to modify, and a number of catalysts can be obtained in a simple two-step synthesis. The activity in the Wittig reaction significantly surpasses previously reported phospholane-based catalysts and the reaction can be conducted with catalyst loadings as low as 1.0 mol percent even at room temperature. Furthermore, a Br?nsted acid additive is no longer required to achieve high yields at these mild conditions. A methyl-substituted phosphetane oxide was employed to synthesize 25 different alkenes with yields of up to 97percent. The methodology has a good functional group tolerance and the reaction can be performed starting with alkyl chlorides, bromides, or iodides. Additionally, it was possible to use poly(methylhydrosiloxane) as the terminal reductant in the catalytic Wittig reaction employing 2-MeTHF as a renewable solvent. The intermediates of the Wittig reaction were analyzed by 31P NMR spectroscopy, and in situ NMR experiments confirmed phosphane oxide as the resting state of the catalyst. Further kinetic investigations revealed a striking influence of the base on the rate of phosphane oxide reduction.

Copper-catalyzed vinylogous aerobic oxidation of unsaturated compounds with air

A mild and operationally simple copper-catalyzed vinylogous aerobic oxidation of β,γ- and α,β-unsaturated esters is described. This method features good yields, broad substrate scope, excellent chemo- and regioselectivity, and good functional group tolerance. This method is additionally capable of oxidizing β,γ- and α,β-unsaturated aldehydes, ketones, amides, nitriles, and sulfones. Furthermore, the present catalytic system is suitable for bisvinylogous and trisvinylogous oxidation. Tetramethylguanidine (TMG) was found to be crucial in its role as a base, but we also speculate that it serves as a ligand to copper(II) triflate to produce the active copper(II) catalyst. Mechanistic experiments conducted suggest a plausible reaction pathway via an allylcopper(II) species. Finally, the breadth of scope and power of this methodology are demonstrated through its application to complex natural product substrates.

Stereoselective Organocatalytic Synthesis of α,α-Difluoro-γ,γ-Disubstituted Butenals

A highly stereoselective reaction of α,α-difluoro-γ,γ-disubstituted butenals 2 bearing two different substituents at the γ position has been developed with an organocatalytic system of l-proline (30 mol %) and salicylic acid (60 mol %). This novel reactio

Enantioselective α-and γ-alkylation of α,β- unsaturated aldehydes using dienamine activation

The enantioselective alkylation of α,β-unsaturated aldehydes with stabilized carbocations as electrophiles via the activation as dienamine intermediates is described. This unique application of dienamine catalysis allows for the first enantioselective γ-a

Stereoselective olefination reactions promoted by Rieke manganese

A study of the advantages of using manganese, an inexpensive and nontoxic metal, to perform stereoselective β-elimination reactions and to promote sequential olefination reactions of aldehydes to obtain α,β- unsaturated esters and amides is presented. Various elimination reactions, all of them characterized by occurring with complete stereoselectivity and in high yields, were performed using active manganese (Mn*) as metalating agent. This ability of manganese has been applied to develop a novel and direct synthesis of (E)-α,β-unsaturated esters or amides and (Z)-α,β-unsaturated α-halo esters and α-choroamides through a Mn*-mediated sequential olefination protocol of aldehydes with dichloro esters or amides and trihalo esters or trichloroamides, respectively. Georg Thieme Verlag Stuttgart.

Highly (E)-selective wadsworth-emmons reactions promoted by methylmagnesium bromide

(Chemical Equation Presented) An experimentally simple protocol for the very highly (E)-selective Wadsworth-Emmons reaction [(E):(Z) selectivities in excess of 180:1 in some cases] of a range of straight-chain and branched aliphatic, substituted aromatic, and base-sensitive aldehydes via reaction with an alkyl diethylphosphonoacetate and MeMgBr is reported.

The first sequential reaction promoted by manganese: Complete stereoselective synthesis of (E)-α,β-unsaturated esters from 2,2-dichloroesters and aldehydes

(Chemical Equation Presented) α,β-Unsaturated esters were obtained with complete control of stereoselectivity utilizing a sequential reaction of dichloroesters with a variety of aldehydes, promoted by active manganese. This methodology is generally applicable, and the C-C double bond can be di- or trisubstituted. A mechanism based on a successive aldol-type reaction/β-elimination is proposed to explain these results.

An efficient synthesis of (E)-α,β-unsaturated ketones and esters with total stereoselectivity by using chromium dichloride

(E)-α,β-Unsaturated ketones 1 or esters 2 can be obtained with complete stereoselectivity by reaction of different 2-chloro-3-hydroxy ketones 3 or esters 4 and CrCl2. A comparative study of the results of synthesis of ketones 1 with CrCl2 or samarium is performed. A mechanism to explain both β-elimination reactions has been proposed.

Synthesis of (E)-α,β-unsaturated esters with total diastereoselectivity by using chromium dichloride

Synthesis of di- and trisubstituted (E)-α,β-unsaturated esters is easily achieved by using chromium dichloride through an elimination reaction of a diastereoisomeric mixture of α-halo-β-hydroxy esters. The starting materials were easily prepared by the aldol reaction of lithium enolates of α-chloroesters with aldehydes. A mechanism to explain this elimination process is proposed.

A highly stereospecific synthesis of (E)-α,β-unsaturated esters

CrCl2-induced olefination of aldehydes using methyl dichloroacetate exclusively generates (E)-α,β-unsaturated esters in excellent yields. The intermediate α-chloro-β-hydroxy adducts could also be isolated in good yields under conditions of limited reagent.