documenta

Structural variations on chiral ligands: new chelanting diphosphines from optical active (1,4)-(Z)- Structural variations on chiral ligands: new chelanting diphosphines from optical active (1,4)-(Z)- 2-butenes. 2-butenes. E. Cesarotti , I. Rimoldi, P. Spalluto Università degli Studi di Milano, Facoltà di Farmacia, Dipartimento di Chimica Inorganica, Metallorganica e Analitica. HO H 3 C CH 3 OH HO H 3 C CH 3 OH H 3 CO CO H 3 C CH 3 O CO CH 3 OH OH H 3 C CH 3 OTs OTs H 3 C CH 3 P Pd P Cl Cl Cl2 Cl1 Pd C11 C41 C4 C1 C2 C3 C111 C121 C211 C221 ' ' Cs PPh 2 PPh 2 H 3 C CH 3 -1.75 ppm -38.98 ppm P Ni P CO CO PPh 2 PPh 2 RhB(Ph) 4 NH OTBS O NH CH O OTBS O NH OTBS CH O O NH OTBS O CH O lin conv (%) = 100% α+β/l = 60/40 α/β = 67/33 H 2 O O O O OH O PA r 2 PA r 2 Ru I + H 2 Conv % = 100% (55h) e.e. % = 66% (Ar = C 6 H 5 ) e.e. % = 64% (Ar = C 8 H 9 ) Conf = R An essential feature: the conformational rigidity of the ligand versus Another essential feature: the modulation of the ligand steric properties by the modification of the substituents on the stereogenic atoms Is it possible to prepare a ligand gathering the conformational rigidity of an atropisomeric ligand with the possibility to modulate steric properties by the modification of the substituents on the stereogenic atoms? enzymatic resolution by LAK Vinyl acetate e.e.% > 98% S,S Commercial available mixture R,R meso H 3 CO CO H 3 C CH 3 OH TsCl NaOH Ni(CO) 4 + P-P (PP)Ni(CO) 2 + 2 CO -20 -20 -10 -10 00 10 10 20 20 30 30 40 40 50 50 60 60 70 70 80 80 90 90 100 100 110 110 120 120 130 130 PPh 2 PPh 2 S S BITIOP (BITIOP)Ni(CO) 2 DPPB R=H PPh 2 PPh 2 R R (DPPB)Ni(CO) 2 Ar 2 PLi -78°C Work in progress: PA r 2 PA r 2 R R R=(CH 3 ) 2 CH-, C 6 H 11 -, C 6 H 5 - PPh 2 PPh 2 Ru I + O O O N H CO OH O O N H CO NH OTBS O e.d.% = 43% e.e.% = 70% Conf = R/R H 2 S,S S,S Pd(PhCN) 2 Cl 2 Ni(CO) 4 PA r 2 PA r 2 H 3 C CH 3 R,R

Upload: peyton

Post on 05-Jan-2016

21 views

Category:

Documents

0 download

Report

Download

Embed Size (px):

DESCRIPTION

Ni(CO) 4 + P-P (PP)Ni(CO) 2 + 2 CO. BITIOP. DPPB R=H. (DPPB)Ni(CO) 2. (BITIOP)Ni(CO) 2. R,R. Pd(PhCN) 2 Cl 2. Ni(CO) 4. b '. a. b. a '. Cs. -38.98 ppm. -1.75 ppm. b. a. H 2. H 2. H 2. e.d.% = 43% e.e.% = 70% Conf = R/R. Conv % = 100% (55h) - PowerPoint PPT Presentation

TRANSCRIPT

Structural variations on chiral ligands: new chelanting diphosphines from optical active (1,4)-(Z)-2-Structural variations on chiral ligands: new chelanting diphosphines from optical active (1,4)-(Z)-2-

butenes.butenes.

E. Cesarotti, I. Rimoldi, P. Spalluto

Università degli Studi di Milano, Facoltà di Farmacia, Dipartimento di Chimica Inorganica, Metallorganica e Analitica.

H3C CH3

H3COCO

H3C CH3

OCOCH3

OH OH

H3C CH3

OTs OTs

H3C CH3

Cl2

Cl1Pd

C11

C41C4C1

C2C3

C111

C121

C211

C221

PPh2 PPh2

H3C CH3

-1.75 ppm

-38.98 ppm

PPh2

PPh2RhB(Ph)4

OTBS

CHO

OTBS

OTBS CHO

OTBS

CHO

linconv (%) = 100%

α+β/l = 60/40

α/β = 67/33

H2O

O O

OH O

PAr2

PAr2Ru

Conv % = 100% (55h)e.e. % = 66% (Ar = C6H5) e.e. % = 64% (Ar = C8H9)Conf = R

An essential feature: the conformational rigidity of the

ligand

versus Another essential feature:the modulation of the ligand steric

properties by the modification of the substituents

on the stereogenic atoms

Is it possible to prepare a ligand gathering the conformational rigidity of an atropisomeric ligand with the possibility to modulate steric properties by the modification of the substituents

on the stereogenic atoms?

enzymatic resolution by

LAKVinyl acetate

e.e.% > 98%S,S

Commercial available mixture

R,R meso

H3COCO

H3C CH3

TsCl

NaOH

Ni(CO)4 + P-P

(PP)Ni(CO)2 + 2 CO