Chiral Phosphine…The Nucleophilic Trigger C.; Lu, X. J. Org. Chem. 1995, 60, 2906-2908 3+2...
Transcript of Chiral Phosphine…The Nucleophilic Trigger C.; Lu, X. J. Org. Chem. 1995, 60, 2906-2908 3+2...
Chiral Phosphine…TheNucleophilic Trigger
3+2 Cycloaddition4+2 Annulation
Cory NewmanFebruary 17, 2006
Wilson, J. E.; Fu, G. C. Angew. Chem. Int. Ed. 2006, 45, 1426-1429 (3+2)Wurz, R. P.; Fu, G. C. J. Am. Chem. Soc. 2005, 127, 12234-12235 (4+2)
3+2 Cycloaddition Reaction
Zhang, C.; Lu, X. J. Org. Chem. 1995, 60, 2906-2908
3+2 Cycloaddition using Alkynoates
Lu, X.; Zhang, C.; Xu, Z. Acc. Chem. Res. 2001, 34, 535-544
PR
R
R
PR
R
R
PR
R
R
PR
R
R
PR
R
R
PR
R
R
Nucleophilic Trigger
C
E
C
E
P
3+2 Cycloaddition Mechanism
Lu, X.; Zhang, C.; Xu, Z. Acc. Chem. Res. 2001, 34, 535-544
Du, Y.; Lu, X.; Yu, Y. J. Org. Chem. 2002, 67, 8901-8905.Du, Y.; Lu, X. J. Org. Chem. 2003, 68, 6463-6465.
Uses of non-Chiral Phosphorus
Xu, Z.; Lu, X. Tetrahedron Lett. 1999, 40, 549-552
First Example of Chiral Phosphorus
Cat. PR3
P
CH3
H3C
PPh Ph
7 8
Zhu, G.; Chen, Z.; Jiang, Q.; Xiao, D.; Cao, P.; Zhang, X. J. Am. Chem. Soc. 1997, 119, 3836-3837
And the Best Chiral Phosphorus is……
Zhu, G.; Chen, Z.; Jiang, Q.; Xiao, D.; Cao, P.; Zhang, X. J. Am. Chem. Soc. 1997, 119, 3836-3837
And the Best Chiral Phosphorus is……
P
CH3
H3C
PPh Ph
7 8
Proposed Transition State
3+2 Cycloaddition of Allenes & Enones
Wilson, J. E.; Fu, G. C. Angew. Chem. Int. Ed. 2006, 45, 1426-1429
Survey of Chiral Phosphorus
A B
(R)-2
PPH2
PPH2
(R)-BINAP
P
(R)-nmdpp
Survey of Chiral Phosphorus
A B
(R)-2
(R)-2
Wilson, J. E.; Fu, G. C. Angew. Chem. Int. Ed. 2006, 45, 1426-1429
Scope
Spiro Example
Wilson, J. E.; Fu, G. C. Angew. Chem. Int. Ed. 2006, 45, 1426-1429
Dienones
Wilson, J. E.; Fu, G. C. Angew. Chem. Int. Ed. 2006, 45, 1426-1429
4+2 Cycloaddition Reaction…Kwon Reaction
Zhu, X.; Lian, J.; Kwon, O. J. Am. Chem. Soc. 2003, 125, 4716-4717
4+2 Cycloaddition Mechanism
Zhu, X.; Lian, J.; Kwon, O. J. Am. Chem. Soc. 2003, 125, 4716-4717
Additional Substrates
Zhu, X.; Lian, J.; Kwon, O. J. Am. Chem. Soc. 2003, 125, 4716-4717
Wurz, R. P.; Fu, G. C. J. Am. Chem. Soc. 2005, 127, 12234-12235
Asymmetric 4+2 Reaction
Allene Scope
Wurz, R. P.; Fu, G. C. J. Am. Chem. Soc. 2005, 127, 12234-12235
Imine Scope
Wurz, R. P.; Fu, G. C. J. Am. Chem. Soc. 2005, 127, 12234-12235
Use in SynthesisW
urz,
R. P
.; Fu
, G. C
. J. A
m. C
hem
. Soc
. 200
5, 1
27, 1
2234
-122
35
Why Not…
Ph
PhP R
Ph
PhP ROR