Evelien Rijnberg

Application of N,S-chelating chiral zinc bis(arenethiolate) complexes as new precursor catalysts in the enantioselective addition of diethylzinc to aldehydes

Abstract The addition of diethylzinc to aldehydes in the presence of a catalytic amount of enantiomerically pure N,S -chelated bis {2-[( R )-1-(dimethylamino)ethyl]phenylthiolato}zinc, afforded the corresponding secondary alcohols in nearly quantitative yields with optical purities of up to 99 % e.e. under mild reaction conditions.

Formation of mixed aryl-, alkyl-lithium aggregates in the heteroatom assisted lithiation of a,a'-dialkyl substituted 1,3-bis[(dimethylamino)methyl]benzene

Abstract The heteroatom assisted lithiation of 1,3-bis[1-(dimethylamino)ethyl]benzene with n-BuLi afforded 2,6-bis[1-(dimethylamino)ethyl]phenyllithium. An X-ray crystal structure determination revealed a dimeric aggregate in which the four benzylic chiral centers are identical, pointing to stereoselective crystallization. In contrast, reaction of 1,3-bis[1-(dimethylamino)propyl]benzene with n-BuLi afforded a dimeric aggregate comprising the parent lithiated compound and n-BuLi in a 1:1 molar ratio. The four Li atoms and the four bridging carbon atoms are arranged in a unique ladder-type C–Li2–C2′–Li2–C framework.

Synthesis and structural characterization of the homoleptic magnesium bis zincate complex Mg(thf) 6[Zn(CH2Ph)3]2

Abstract The addition of Mg(CH2Ph)2(thf)2 to a thf solution of Zn(CH2Ph)2 yields the zincate complex Mg(thf)6[Zn(CH2Ph)3]2 (1), which has been characterized by X-ray crystallography and NMR. Complex 1 is cleaved by tmeda into a 1:2 mixture of Mg(CH2Ph)2(tmeda) and Zn(CH2Ph)2(tmeda).

Heteroleptic metallacyclic potassium organodiamido zincate complex. Synthesis and structure of polymeric {[K(thf)][MeZn(ButNCHCHNBut)]}n

The reaction of the C–C coupled dimer of two neutral organozinc radicals, [MeZn(ButNCHCH(NBut)CH(NBut)CHNBut)ZnMe]1, with potassium in tetrahydrofuran affords the metallacyclic neteroleptic potassium organodiamido zincate K[MeZn(ButNCHCHNBut)]2 quantitatively, which exists in the solid state (X-ray crystallography) as a linear polymer formed by alternating potassium cations and organodiamidozincate anions.