134268-36-3

Upstream product

• 117-99-7 2-Hydroxybenzophenone 
• 134268-50-1 2-isopropoxybenzophenone hydrazone 

Downstream Products

• 101168-75-6 2,2-dimethyl-3-phenyl-2,3-dihydro-benzofuran 
• 134268-46-5 2-(2-isopropoxyphenyl)-2-phenylethanol 
• 134268-45-4 2-isopropoxyphenyl(phenyl)methyl methyl ether 
• 134268-40-9 cyclohexyl(2-isopropoxyphenyl)phenylmethane 

Relevant academic research and scientific papers

Synthesis of Benzodihydrofurans by Asymmetric C?H Insertion Reactions of Donor/Donor Rhodium Carbenes

Metal carbenes appended with two electron-donating groups, known as “donor/donor” carbenes, undergo diastereo- and enantioselective rhodium-catalyzed C?H insertion reactions with ether substrates to form benzodihydrofurans. Unlike the reactions of metal carbenes with electron-withdrawing groups attached, the attenuated electrophilicity enables these reactions to be conducted in Lewis basic solvents (e.g., acetonitrile) and in the presence of water. The diazo precursors for these species are prepared in situ from hydrazone using a mild and chemoselective oxidant (MnO2). Although this sequence often can be performed in one-pot, control experiments have elucidated why a “two-pot” process is often more efficient. A thorough screening of achiral catalysts demonstrated that sterically encumbered catalysts are optimal for diastereoselective reactions. Although efficient insertion into allylic and propargylic C?H bonds is observed, competing dipolar cycloaddition processes are noted for some substrates. The full substrate scope of this useful method of benzodihydrofuran synthesis, mechanisms of side reactions, and computational support for the origins of stereoselectivity are described.

Generation and Reactions of 2-Alkoxydiphenylcarbenes in Fluid Solution and Rigid Matrices

Irradiation of 2-alkoxydiphenyldiazomethanes 1 in cyclohexane at room temperature produced 3-phenyldihydrobenzofurans 3 presumably as a result of intramolecular C-H insertion of 2-alkoxydiphenylcarbenes 2.Irradiation of compounds 1 in cyclohexane matrix at -196 deg C gave intermolecular C-H insertion products 4 at the expense of benzofurans 3.The formation of products 4 is explicable in terms of H-atom tunnelling to the triplet state of carbenes 2, followed by coupling of the resulting radical pairs.Product ratios 3:4 were somewhat sensitive to the bulk of the alkoxy group at the 2-position.This can be explained in terms of the matrix effect on the relative population of the rotational isomers of the carbene 2.Irradiation of compounds 1 in methanol at room temperature afforded O-H insertion products 5 almost exclusively, whereas irradiation in methanol matrix at -196 deg C gave C-H insertion products 6 along with other products 3 and 5.