Page 957 - Advanced Organic Chemistry Part B - Reactions & Synthesis

Scheme 10.11. Chiral Dirhodium Catalysts 933

1 a 2 a 3 b SECTION 10.2
O O N Reactions Involving
N CO 2 CH 3 CO 2 CH 3 O N CO 2 CH 2 C(CH 3 ) 3 Carbenes and Related
Rh Rh Rh Rh Rh Rh Intermediates
CH 3 O 2 C N O CH 3 O 2 C N O (CH 3 ) 3 CCH 2 O 2 C N O
11-2 11-3
11-1
Rh 2 (5S–NEPY)4
Rh 2 (5R–MePY) 4
Rh 2 (5S–MePY) 4
4 c 5 d CH 3 O 6 d PhCH 2 O
N N
O
O N
O N CO 2 CH 3
O N CO 2 CH 3 CO 2 CH 3 Rh Rh
Rh Rh
Rh Rh N O
CH 3 O 2 C N O CH 3 O 2 C
CH 3 O 2 C N O
N
N
O CH 2 Ph
11-4 CH 3 11-5 O
O 11-6
Rh 2 (4S–MEOX) 4 Rh 2 (4S–MACIM) 4 Rh 2 (4S–MPAIM) 4
7 e 8 f g
9
N N
PhSO 2 C 12 H 25 SO 2
N
ArSO 2
O O NSO 2 Ar O
O O O O O
R O Rh O R Rh O R Rh O R
O Rh O R O Rh O O Rh O O
O O O
O O
R 11-9
N SO 2 Ph 11-7 N SO 2 C 12 H 25 Ar = 2,4,6–tri–iso–
propylphenyl
11-8
R = 1–benzenesulfonyl–S–prolinate R = 1–(4–dodecylbenzenesulfonyl)– R = duplicate of bidentate
prolinate
ligand
Rh 2 (OSP) 4
Rh 2 (S–biTISP) 2
a. M. P. Doyle, R. J. Pieters, S. F. Martin, R. E. Austin, P.. J. Oalmann, and P. Mueller, J. Am. Chem. Soc., 113, 1423
(1991); M. P. Doyle, W. R. Winchester, J. A. A. Hoorn, V. Lynch, S. H. Simonsen, and R. Ghosh, J. Am. Chem. Soc.,
115, 9968 (1993).
b. M. P. Doyle, A. van Oeveren, L. J. Westrum, M. N. Protopopova, and W. T. Clayton, Jr., J. Am. Chem. Soc., 113, 8982
(1991).
c. M. P. Doyle, A. B. Dyatkin, M. N. Protopopova, C. I. Yang, C. S. Miertschin, W. R. Winchester, S. H. Simonsen,
V. Lynch, and R. Ghosh, Recl. Trav. Chim. Pays-Bas, 114, 163 (1995).
d. M. P. Doyle, A. B. Dyatkin, G. H. P. Roos, F. Canas, D. A. Pierson, A. van Basten, P. Mueller, and P. Polleux, J. Am.
Chem. Soc., 116, 4507 (1994).
e. M. A. McKervey and T. Ye, J. Chem. Soc., Chem. Commun., 823 (1992).
f. H. M. L. Davies and D. K. Hutcheson, Tetrahedron Lett., 34, 7243 (1993); H. M. L. Davies, P. R. Bruzinski, D. H. Lake,
N. Kong, and M. J. Fall, J. Am. Chem. Soc., 118, 6897 (1996).
g. H. M. L. Davies and S. A. Panaro, Tetrahedron Lett., 40, 5287 (1999).
Scheme 10.12 gives some examples of enantioselective cyclopropanations. Entry 1
uses the bis-t-butyloxazoline (BOX) catalyst. The catalytic cyclopropanation in Entry
2 achieves both stereo- and enantioselectivity. The electronic effect of the catalysts
(see p. 926) directs the alkoxy-substituted ring trans to the ester substituent (87:13
ratio), and very high enantioselectivity was observed. Entry 3 also used the t-butyl-
BOX catalyst. The product was used in an enantioselective synthesis of the alkaloid
quebrachamine. Entry 4 is an example of enantioselective methylene transfer using the
tartrate-derived dioxaborolane catalyst (see p. 920). Entry 5 used the Rh [5(S -MePY] 4
2