80603-33-4Relevant academic research and scientific papers
A Planar-Chiral Phosphino(alkenyl)ferrocene for Suzuki-Miyaura C-C Coupling Reactions
Schaarschmidt, Dieter,Grumbt, Martin,Hildebrandt, Alexander,Lang, Heinrich
supporting information, p. 6676 - 6685 (2016/02/19)
Planar-chiral phosphinoferrocene [Fe(η5-C5H3-1-PPh2-2-(E)-CH=CHPh)(η5-C5H5)] (4) was applied in the presence of palladium in Suzuki-Miyaura couplings for the synthesis of sterically congested biaryls. The catalytic activity arises from homogeneous palladium phosphine complexes, of which the potential pre-catalyst [Pd(4)2Cl2] was characterized structurally. The catalytic system is excellently suited for the synthesis of tri-ortho-substituted biaryls under mild conditions (0.1 mol-%, 50-100 C), whereas its application towards the synthesis of tetra-ortho-substituted biaryls is quite limited. Comparing the performance of the reaction with 4 as catalyst and a range of substrates with differing ortho substituents suggests that transmetalation is rate determining. Complex (Sp)-4 was used in atropselective couplings, wherein enantioenrichments of up to 36 % were achieved. The stereoselectivity depends to some extent on the steric properties of the boronic acids; however, slight changes at the aryl halides influence the enantioselectivity.
Practical Synthesis of 1,1'-Binaphtyl-2-carboxylic Acids via Side Chain Oxidation of 2-Methyl-1,1'-binaphtyls
Miyano, Sotaro,Okada, Shin-ichi,Suzuki, Toshiyuki,Handa, Shigeru,Hashimoto, Harukichi
, p. 2044 - 2046 (2007/10/02)
Four 1,1'-binaphtyl-2-carboxylic acids were obtained in 38-53 percent isolated yield via three-stage oxidation of 2-methyl-1,1'-binaphtyls, that is, i) NBS-bromination to benzylic bromides, ii) treatment with sodium salt of 2-nitropropane to aldehydes, and iii) KMnO4-oxidation to carboxylic acids.
