TY - JOUR
T1 - Imide-amide rearrangement of cyclic phosphorimidates
T2 - A mechanistic study
AU - Cabrita, Eurico J.
AU - Afonso, Carlos A. M.
AU - Santos, António G.
PY - 2001/4/1
Y1 - 2001/4/1
N2 - Studies aimed at the development of new synthetic pathways for the preparation of chiral cyclic oxaza and diaza phosphoramides suitable for use in asymmetric chemistry led us to the investigation of the imide-amide rearrangement of cyclic phosphorimidates. As a result of this work new types of oligomeric organophosphorus compounds, formed by a novel 1,4-addition type ring opening polymerisation, were identified. These compounds are the stable intermediates of the imide-amide rearrangement, which upon heating yield the previously reported rearranged product. A detailed study of the mechanism of the Lewis acid catalysed imide-amide rearrangement and stereochemical control of the final products is reported. As a result, the full mechanism was elucidated and evidence of retention of configuration at the rearranged carbon atom is presented. Substituent effects were rationalised based on molecular modelling calculations.
AB - Studies aimed at the development of new synthetic pathways for the preparation of chiral cyclic oxaza and diaza phosphoramides suitable for use in asymmetric chemistry led us to the investigation of the imide-amide rearrangement of cyclic phosphorimidates. As a result of this work new types of oligomeric organophosphorus compounds, formed by a novel 1,4-addition type ring opening polymerisation, were identified. These compounds are the stable intermediates of the imide-amide rearrangement, which upon heating yield the previously reported rearranged product. A detailed study of the mechanism of the Lewis acid catalysed imide-amide rearrangement and stereochemical control of the final products is reported. As a result, the full mechanism was elucidated and evidence of retention of configuration at the rearranged carbon atom is presented. Substituent effects were rationalised based on molecular modelling calculations.
KW - Heterocycles
KW - Imide-amide rearrangement
KW - Mechanism elucidation
KW - Molecular modeling
KW - Polymers
UR - http://www.scopus.com/inward/record.url?scp=0035312949&partnerID=8YFLogxK
U2 - 10.1002/1521-3765(20010401)7:7<1455::AID-CHEM1455>3.0.CO;2-U
DO - 10.1002/1521-3765(20010401)7:7<1455::AID-CHEM1455>3.0.CO;2-U
M3 - Article
C2 - 11330900
AN - SCOPUS:0035312949
SN - 0947-6539
VL - 7
SP - 1455
EP - 1467
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 7
ER -