Nature of intermediates in organo-SOMO catalysis of alpha-arylation of aldehydes.
The intramolecular alpha-arylation of aldehydes via organo-SOMO catalysis was investigated using density functional theory (B3LYP and M06-2X functionals). The geometries, spin densities, Mulliken charges, and molecular orbitals of the reacting enamine radical cations were analyzed, and the nature of the resulting cyclized radical cation intermediates was characterized. In agreement with experimental observations, the calculated 1,3-disubstituted aromatic system shows ortho selectivity, while the 1,3,4-trisubstituted systems show para, meta (instead of ortho, meta) selectivity. The selectivity change for the trisubstituted rings is attributed to a distortion of the ortho substituents in the ortho, meta cyclization transition structures that causes a destabilization of these isomers and therefore results in selectivity for the para, meta product.
Um
Joann M
JM
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
Gutierrez
Osvaldo
O
Schoenebeck
Franziska
F
Houk
K N
KN
MacMillan
David W C
DW
D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization
D000447:Aldehydes
J Chem Theory Comput. 2008 Dec 9;4(12):1996-2000
26620472
J Am Chem Soc. 2009 Feb 18;131(6):2086-7
19173649
J Am Chem Soc. 2009 Aug 19;131(32):11332-4
19627154
Phys Chem Chem Phys. 2008 May 21;10(19):2747-57
18464990
Science. 2007 Apr 27;316(5824):582-5
17395791
J Am Chem Soc. 2008 Dec 10;130(49):16494-5
19049447
J Am Chem Soc. 2008 Jan 16;130(2):398-9
18095690
J Phys Chem A. 2008 Feb 14;112(6):1095-9
18211046
J Am Chem Soc. 2009 Aug 26;131(33):11640-1
19639997
J Am Chem Soc. 2007 Jun 6;129(22):7004-5
17497866
Chemistry. 2009 Aug 24;15(34):8443-8
19444824