Chiral Diazaligands for Asymmetric Synthesis by Diego Savoia (auth.), Marc Lemaire, Pierre Mangeney (eds.)

By Diego Savoia (auth.), Marc Lemaire, Pierre Mangeney (eds.)

The use of phosphine derivatives has traditionally brought on the large improvement of catalysis (both non-asymmetric and asymmetric). even though the chemistry of amines is extra documented, using nitrogen-containing ligands basically seemed lately. however, over the last ten years, the consequences describing chiral diamine arrangements and their makes use of in uneven catalysis and synthesis are expanding speedier than their phosphorus opposite numbers. The reader will locate during this quantity the latest tools for the synthesis of chiral diamines in addition to their purposes in uneven catalysis of CC bond formation. specific realization might be given to spartein and derivatives of such diamines. lately, the actual houses and the chemistry of amines allowed to procure catalysts effortless to split and recycle and new varieties of ligands equivalent to diaminocarbenes, ureas and thioureas. eventually, the complexing homes of a few diamines allowed the formation of complexes with chirality "at the steel " that's of significant theoretical curiosity and offers various power applications.

Show description

Read Online or Download Chiral Diazaligands for Asymmetric Synthesis PDF

Similar chemistry books

Compr. Heterocyclic Chem. III Vol. 3 Five-membered Rings with One Heteroatom

Content material: v. 1. 3-membered heterocycles, including all fused structures containing a 3-membered heterocyclic ring / quantity editor, Albert Padwa -- v. 2. 4-membered heterocycles including all fused structures containing a 4-membered heterocyclic ring / quantity editor, Christian Stevens -- v.

Handbook of Magnetic Materials, Volume 14

Magnetoelectronics is a unique and quickly constructing box. This new box is usually often called spin-electronics or spintronics. It comprises spin-utilizing units that desire neither a magnetic box nor magnetic fabrics. In semiconductor units, the spin of the companies has in simple terms performed a really modest function thus far simply because good tested semiconductor units are non-magnetic and convey in simple terms negligible results of spin.

Cobalt Oxides: From Crystal Chemistry to Physics

Unprecedented within the breadth and intensity of its assurance of all vital points, this ebook systematically treats the digital and magnetic homes of stoichiometric and non-stoichiometric cobaltites in either ordered and disordered stages. Authored through a pioneer and a emerging megastar within the box, the monograph summarizes, organizes and streamlines the differently difficult-to-obtain info in this subject.

Additional info for Chiral Diazaligands for Asymmetric Synthesis

Sample text

Similarly, the oxazolidine (R,S)-147, obtained as a mixture of epimers at C2 from N,N-dibenzyl (R)-phenylalaninal and N-benzyl (S)-valinol, reacted with Grignard reagents to form in situ the iminium ion 148, from which the diamino alcohols 149 were produced as a single diastereomer [71] (Scheme 23). On the other hand, when the oxazolidine derived from the (S)-aldehyde was used, the diamino alcohol was obtained as a 70 : 30 mixture of diastereomers. Alhough the preparation of the primary 1,2-diamines was not explored in that paper, compounds 149 would be the precursors of the syn 1,2-diamine Scheme 23 Double asymmetric induction in the addition of Grignard reagents to chiral α-amino imines and α-amino iminium ions Progress in the Asymmetric Synthesis 29 150, by selective oxidative removal of the chiral auxiliary and subsequent hydrogenolysis of the N-benzyl substituents.

The addition of the more reactive organolithium reagents to the diimine in THF at – 78 ◦ C required quenching of the reaction mixtures at low temperature with deaerated water. In fact, since the dilithium 1,2-diamides are in equilibrium with the α-amido C radical above 0 ◦ C (Scheme 3), the reaction of these intermediates with oxygen dissolved in water during quenching led ultimately to monoimines [121]. Generally, the reactions with the lithium reagents showed low stereocontrol; however, the two main syn diastereomers of the 1,2-diamines 248b, 248f and 248g, but not 248h (R is vinyl), could be separated by column chromatography and isolated in a pure state with moderate yields.

Savoia erate efficiency and diastereoselectivity to give the 2-(1aminoalkyl)pyrrolidines derivatives 142 and 143 [69] (Scheme 22). , the sulfinimine 144 [70]. In this case, the R configuration at the sulfur of the chiral auxiliary, N-tert-butanesulfinamide, matched with the S configuration of the starting α-amino aldehyde, allowing complete stereocontrol to be achieved in the preparation of the diamine derivatives 145 by the addition of trifluoromethyl anion, which was formed from trifluoromethyltrimethylsilane in the presence of tetramethylammonium fluoride (Scheme 23).

Download PDF sample

Rated 4.35 of 5 – based on 15 votes