synthesized in a similar way using 1 equiv of AlCl3. Compounds 2a,b and 3a are monomeric four-coordinate mono[bis(oxazolinato)aluminum] complexes, on the basis of X-ray analyses for 2b and 3a and NMR data for 2a,b and 3a. The dimethylaluminum complexes BOX-Me2}AlMe2 (2a) and BOX-(S)-iPr}AlMe2 (2b) react in C6D5Br with B(C6F5)3 to yield the quantitative formation of cations BOX-Me2}AlMe+ (4a+) and BOX-(S)-iPr}AlMe+
trisoxazoline and bisthiazoline based ligands have been developed,which are absent of chiral motif on the parent skeleton and containa chiral backbone on sidearm. The ligands promote the amine nucleophilic ringopeningreaction of 1,1‐cyclopropane diesters smoothly, furnishing the γ‐amino acid derivatives in high yield with moderate to good enantioselectivity.
A method for synthesis of secondary alcohols is provided for pharmaceutical secondary alcohol by addition of organoboronic acids with aldehydes in presence of the cobalt ion and bidentate ligands as the catalyst. In addition, an enantioselective synthesis method for secondary alcohols is also herein provided in the present invention. The present invention has advantages in using less expensive cobalt ion and commercially available chiral ligands as the catalyst, wide scope of organoboronic acids and aldehydes compatible with this catalytic reaction and achieving excellent yields and/or enantiomeric excess.
作者:Aradhana Pindwal、KaKing Yan、Smita Patnaik、Bradley M. Schmidt、Arkady Ellern、Igor I. Slowing、Cheolbeom Bae、Aaron D. Sadow
DOI:10.1021/jacs.7b09521
日期:2017.11.22
Homoleptic tris(alkyl) rareearth complexes LnC(SiHMe2)3}3 (Ln = La, 1a; Ce, 1b; Pr, 1c; Nd, 1d) are synthesized in high yield from LnI3THFn and 3 equiv of KC(SiHMe2)3. X-ray diffraction studies reveal 1a–d are isostructural, pseudo-C3-symmetric molecules that contain two secondary Ln↼HSi interactions per alkyl ligand (six total). Spectroscopic assignments are supported by comparison with LnC(SiDMe2)3}3 and
bioinorganic model studies. Here, it is shown that simple bis(oxazoline)s (BOXs), which are classified among the so-called “privileged ligands”, provide a suitable scaffold for supporting such biomimetic copper/dioxygen chemistry. Three derivatives R,HBOX-Me2 (R = H, Me, tBu) with different backbone substituents have been used. Their bis(oxazoline)-copper(I) complexes bind dioxygen to yield biomimetic