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The 3‐Acetyloxaphosphirane/1,3,2‐Dioxaphosphol‐4‐ene Rearrangement
Author(s) -
Abdrakhmanova Liliya,
Schnakenburg Gregor,
Espinosa Arturo,
Streubel Rainer
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201301169
Subject(s) - chemistry , heterolysis , pericyclic reaction , oxonium ion , sigmatropic reaction , diradical , cope rearrangement , bond cleavage , stereochemistry , ene reaction , medicinal chemistry , heteroatom , ring (chemistry) , singlet state , organic chemistry , ion , physics , nuclear physics , excited state , catalysis
Abstract An Li/Cl phosphinidenoid complex, obtained by chlorine/lithium exchange from a [dichloro(organo)phosphane]tungsten(0) complex, reacted with aliphatic dicarbonyl derivatives to provide oxaphosphirane complexes, a 1,3,2‐dioxaphosphol‐4‐ene complex, and a P ‐alkoxyphosphane complex; the latter is formally derived from the enol form of the β‐diketone. DFT calculations on the ring‐expansion rearrangement support a preferred mechanism involving a pericyclic [1,3] shift of the phosphorus fragment in an oxaphosphirane complex rather than a stepwise diradical or ionic mechanism. The latter is slightly unfavored (ΔΔ E ‡ = 2.2 kcal/mol) and involves heterolytic P–C bond cleavage to give a methylene oxonium phosphanide intermediate and cyclization through a low‐lying transition state featuring an unusual linear C–O–P geometry.