67859-06-7Relevant academic research and scientific papers
Rhodium-catalyzed cyclopropanations of 2-aryl-2H-chromenes with dialkyl malonate esters. A comparison of α-diazo derivatives and phenyliodonium ylides
Stokes, Sean,Mustain, Rachel,Pickle, Lydia,Mead, Keith T.
supporting information; experimental part, p. 3890 - 3893 (2012/09/08)
Rhodium-catalyzed reactions of 2-aryl-substituted 2H-chromenes with α-diazo esters prepared from dimethyl and tert-butyl methyl malonates were investigated, and the results were compared with reactions carried out with phenyliodonium ylides prepared from the same esters. The phenyliodonium ylide prepared from dimethyl malonate was found to give superior yields of cyclopropane products compared to the corresponding α-diazo equivalent. However, this result was reversed with tert-butyl methyl malonate when Rh 2(S-TBSP)4 was used to decompose the diazo compound. All reactions gave 1,1-cyclopropane diesters as single diastereomers.
