1,4-Addition of Nucleophiles to -Unsaturated Carbonyl Compounds - Carbohydrates: Tools for Stereoselective Synthesis - page 262

Table 12.1

Representative results of conjugate addition of alkyl donors to 2-cyclohexenone. a)f )

O

O

1 mol%Cu source, 2 mol% ligand*

R 1 = Et, Me

+

1.4 equiv MR 1 n

*

R 1

Solvent

Entry Ligand Precursor MR 1 n Solvent

P,P donors 3a Cu(OTf) 2 f)

(0.5 mol.%)

1 ZnEt 2 CH 2 Cl 2

R 1 = R 2 = H

O
O

O

OO P

3b Cu(OTf) 2 f)

(0.5 mol.%)

P

2 ZnEt 2 CH 2 Cl 2

R 1 t Bu, R 2

O = = OMe

O

3c Cu(OTf) 2 f)

(0.5 mol.%)

O O

3 ZnEt 2 CH 2 Cl 2

R 1 R 2 t Bu = =

3d
(S) ax R 3

Cu(OTf) 2 f) 4 ZnEt 2 CH 2 Cl 2

= H

3e
(R) ax R 3 = H

5 Cu(OTf) 2 f) ZnEt 2 CH 2 Cl 2

3f
(R) ax R 3 = SiMe 3

6 Cu(OTf) 2 f) ZnEt 2 CH 2 Cl 2

Ph 2 PO OPPh 2

O

[CuMeCN) 4 ]
BF 4 f)

7 4 AlEt 3 CH 2 Cl 2

O O

Ph 2 PO

O

[CuMeCN) 4 ]
BF 4 f)

8 14 AlEt 3 CH 2 Cl 2

O O

Ph 2 PO