1036645-56-3Relevant academic research and scientific papers
Chiral Lithium Amido Aryl Zincates: Simple and Efficient Chemo- and Enantio-Selective Aryl Transfer Reagents
Chaumont-Olive, Pauline,Rouen, Mathieu,Barozzino-Consiglio, Gabriella,Ben Abdeladhim, Amel,Maddaluno, Jacques,Harrison-Marchand, Anne
, p. 3193 - 3197 (2019)
An enantioselective aryl transfer is promoted using chiral tricoordinated lithium amido aryl zincates that are easily accessible reagents and whose chiral appendage is simply recovered for reuse. The arylation reaction is run in good yields (60 % average on twenty substrates) and high enantiomeric excesses (95 % ee average). This occurs whatever the ortho, meta, or para substituent borne by the substrate and a complete chemoselectivity is observed with respect to the aldehyde function. Sensitive groups such as nitriles, esters, ketones, and enolisable substrates resist to the action of the ate reagent, warranting a large scope to this methodology.
Catalytic enantioselective synthesis of diarylmethanols from Aryl bromides and aldehydes by using organolithium reagents
Nakagawa, Yuya,Muramatsu, Yusuke,Harada, Toshiro
experimental part, p. 6535 - 6538 (2011/02/22)
A general method has been developed for preparing enantioenriched secondary alcohols by starting from aryl bromides and aldehydes. Aryl bromides were first treated with BuLi, and the resulting aryllithium reagents were mixed with titanium tetraisopropoxide and magnesium bromide. The reaction of aldehydes with the resulting mixed titanium reagents, in the presence of 3-(3,5- diphenylphenyl)-H8-BINOL (2 mol-%) and titanium tetraisopropoxide, furnished the corresponding alcohols in high enantioselectivities and in high yields. Copyright
Catalytic enantioselective alkylation and arylation of aldehydes by using grignard reagents
Muramatsu, Yusuke,Kanehira, Shinichi,Tanigawa, Masato,Miyawaki, Yuta,Harada, Toshiro
experimental part, p. 19 - 32 (2010/03/25)
We have developed an efficient and practical method for the catalytic enantioselective alkylation and arylation of aldehydes by using Grignard reagents in combination with titanium tetraisopropoxide. Grignard reagents and titanium tetraisopropoxide are mixed in a molar ratio of ca. 1:2. In the presence of catalyst (24mol%), which is formed in situ from a BINOL ligand 4a and 4b and titanium tetraisopropoxide, the resulting mixed titanium reagents undergo addition to aldehydes with high enantioselectivities (typically >90% ee) and high yields. The method is applicable to various combination of aldehydes (R1CHO; R1 = aryl, heteroaryl, 1-alkenyl, and alkyl) and Grignard reagents (R2MgX; R2 = primary alkyl and aryl). Thus, a variety of enantiomerically enriched secondary alcohols (R1CH*(OH)R2) can be prepared. It has also been demonstrated that functionalized aryl Grignard reagents can be employed to generate highly functionalized diarylmethanols. The preparative utility of the method has been shown by the fact that the reaction is operationally simple, can be carried out on a 10-mmol scale without any difficulty, and the ligands can be readily recovered.
