5293-22-1

Upstream product

• 5392-10-9 2-bromo-4,5-dimethoxybenzaldehyde 
• 925-90-6 ethylmagnesium bromide 
• 74-96-4 ethyl bromide 
• 2386-64-3 ethylmagnesium chloride 
• 120-14-9 3,4-dimethoxy-benzaldehyde 

Downstream Products

• 1354364-45-6 3-(2-bromo-4,5-dimethoxyphenyl)pentan-3-ol 
• 125575-56-6 1-(2-bromo-4,5-dimethoxyphenyl)propan-1-one 

Relevant academic research and scientific papers

On the identity of a neo-lignan from the fruits of Virola sebifera

7-(3,4-Dimethoxyphenyl) 6-methylindeno[5,6-d][1,3]dioxol-5-one 2 has been reported as a neo-lignan isolated from the fruits of Virola sebifera. However, physical and spectroscopic data obtained from two synthetic samples of 2 do not match those quoted in the isolation paper. Data obtained from an isomer, 3-(benzo[1,3]dioxol-5-yl)-5,6-dimethoxy-2-methylinden-1-one 10, are in closer agreement but the 13C NMR spectrum reveals many inconsistencies.

Phosphine- and water-promoted pentannulative aldol reaction

Herein, an efficient metal-free intramolecular aldol reaction for the synthesis of an unusual class of cyclopentanoids is described. The reaction of α-substituted dienones tethered with ketones in the presence of tributylphosphine and water provided aldols. The role of water was realised to be crucial for this transformation. Furthermore, isotopic labeling experiments provided vital information about the reaction mechanism.

A domino palladium-catalyzed C-C and C-O bonds formation via dual O-H bond activation: Synthesis of 6,6-dialkyl-6 H -benzo[ c ]chromenes

An efficient Pd-catalyzed domino reaction of α,α-dialkyl-(2- bromoaryl)methanols to 6,6-dialkyl-6H-benzo[c]chromenes is presented. Their formation can be explained via a five membered Pd(II)-cycle that efficiently involves a domino homocoupling with the second molecule, β-carbon cleavage, and finally intramolecular Buchwald-Hartwig cyclization. This domino process effectively involves breaking of five σ-bonds (2C-Br, 2O-H, and a C-C) and formation of two new σ-bonds (C-C and C-O). This mechanistic pathway is unprecedented and further illustrates the power of transition metal catalysis.