TY - JOUR
T1 - Addition of a phosphinidene complex to C=N bonds
T2 - P-ylides, azaphosphiridines, and 1,3-dipolar cycloadditions
AU - Vlaar, Mark J.M.
AU - Valkier, Pieter
AU - De Kanter, Frans J.J.
AU - Schakel, Marius
AU - Ehlers, Andreas W.
AU - Spek, Anthony L.
AU - Lutz, Martin
AU - Lammertsma, Koop
PY - 2001/8/17
Y1 - 2001/8/17
N2 - The terminal phosphinidene complex PhPW(CO)5 adds to the imine bond of PhHC=N-Ph to give 3-membered ring azaphosphiridines, which undergo ring-expansion with an additional imine to yield a set of four isomeric five-membered ring diazaphospholanes. Treatment with the diimines PhHC=N(CH2)n-N=CHPh (n=2,3,4) results instead - in all three cases - in only a single isomer of the (CH2)n, bridged diazaphospholane. For n = 2 or 3, this aminal group is easily hydrolyzed to afford new 6- and 7-membered ring heterocycles. No intermediate azaphosphiridine complex is observed during the addition reaction to the diimines. B3LYP/6-31G* calculations on an unsubstituted, uncomplexed system suggest that the initially formed P,N-ylide of the H2C=N-(CH)2-N=CH2 diimine both kinetically and thermodynamically favors an intramolecular 1,3-dipolar cyclo-addition over an imine insertion into the CPN ring of an intermediate azaphosphiridine. Single-crystal X-ray structures for the (CH2)2-bridged azaphospholane complex and the HCl adduct of the 7-membered hydrolysis product are presented.
AB - The terminal phosphinidene complex PhPW(CO)5 adds to the imine bond of PhHC=N-Ph to give 3-membered ring azaphosphiridines, which undergo ring-expansion with an additional imine to yield a set of four isomeric five-membered ring diazaphospholanes. Treatment with the diimines PhHC=N(CH2)n-N=CHPh (n=2,3,4) results instead - in all three cases - in only a single isomer of the (CH2)n, bridged diazaphospholane. For n = 2 or 3, this aminal group is easily hydrolyzed to afford new 6- and 7-membered ring heterocycles. No intermediate azaphosphiridine complex is observed during the addition reaction to the diimines. B3LYP/6-31G* calculations on an unsubstituted, uncomplexed system suggest that the initially formed P,N-ylide of the H2C=N-(CH)2-N=CH2 diimine both kinetically and thermodynamically favors an intramolecular 1,3-dipolar cyclo-addition over an imine insertion into the CPN ring of an intermediate azaphosphiridine. Single-crystal X-ray structures for the (CH2)2-bridged azaphospholane complex and the HCl adduct of the 7-membered hydrolysis product are presented.
KW - Complexed phosphinidene cycloaddition
KW - Density functional calculations
KW - Heterocycles
KW - Ylides
UR - http://www.scopus.com/inward/record.url?scp=0035902815&partnerID=8YFLogxK
U2 - 10.1002/1521-3765(20010817)7:16<3551::AID-CHEM3551>3.0.CO;2-M
DO - 10.1002/1521-3765(20010817)7:16<3551::AID-CHEM3551>3.0.CO;2-M
M3 - Article
C2 - 11560326
AN - SCOPUS:0035902815
SN - 0947-6539
VL - 7
SP - 3551
EP - 3557
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 16
ER -