1404591-81-6Relevant articles and documents
On the configurational stability of chiral heteroatom-substituted [D 1]Methylpalladium complexes as intermediates of stille and suzuki-miyaura cross-coupling reactions
Malova Krizkova, Petra,Hammerschmidt, Friedrich
supporting information, p. 5143 - 5148 (2013/11/06)
Enantiomerically pure (S)-tributylstannyl[D1]methanol and (R)- and (S)-tributylstannyl[D1]methyl benzoates were Stille-coupled with bromobenzene and benzoyl chloride in 1,4-dioxane and toluene using [(Ph 3P)4Pd] or [(Ph3P)2PdCl2] either alone or in combination with CuCN as cocatalyst at temperatures up to 80 °C. The products were found to be enantiomerically pure. (R)- and (S)-N-(tributylstannyl[D1]methyl)phthalimides gave enantiomerically pure products with benzoyl chloride, but with bromobenzene protected phenyl[D1]methylamines gave products of only 52-69 % ee depending on the solvent used. Tributyl(thio[D1]methyl)stannanes could not be Stille-coupled with benzoyl chloride or with bromobenzene. Similarly, dimethyl phenyl[D1]methylboronate underwent a Suzuki-Miyaura coupling with bromobenzene to give phenyl[D1]methylsilane with 99 % ee. All couplings followed a retentive course and, except in one case, the intermediate [XCHDPdLn] complexes were found to be microscopically configurationally stable. Stille coupling of enantiomerically pure tributylstannyl[D1]methanol, its benzoate, and the N-(tributylstannyl[D1]methyl)phthalimide with bromobenzene and benzoyl chloride furnished products containing a chiral XCHD group. Overall net retention of configuration was found in all cases.
On the preparation and determination of configurational stability of chiral thio- and bromo[D1]methyllithiums
Wieczorek, Anna,Hammerschmidt, Friedrich
, p. 10021 - 10034 (2013/01/15)
Thio- and bromo[D1]methyllithiums (ee 99%) were generated from the respective stannanes by tin-lithium exchange at temperatures ranging from 0 to -95 °C. Thio[D1]methyllithiums 6 were found to be microscopically configurationally labile on the time scale of the thiophosphate-α-mercaptophosphonate rearrangement even at -95 °C. Thio[D1]methyllithiums 13a and 13b underwent a thia-[2,3]-Wittig rearrangement down to -95 °C and 13b only down to -50 °C. The former were microscopically configurationally stable below -95 °C, and the latter racemized completely at -50 °C. Chiral bromo[D1]methyllithiums are chemically unstable at -78 °C but microscopically configurationally stable at the time scale of their addition to benzaldehyde and acetophenone.
