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Reactivity of Carbonyl‐Functionalized Phosphaalkenes RC(O)P=C(NMe 2 ) 2 (R = t Bu, Ph) towards Electrophiles
Author(s) -
Weber Lothar,
Uthmann Stefan,
Stammler HansGeorg,
Neumann Beate,
Schoeller Wolfgang W.,
Boese Roland,
Bläser Dieter
Publication year - 1999
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/(sici)1099-0682(199912)1999:12<2369::aid-ejic2369>3.0.co;2-s
Subject(s) - chemistry , electrophile , medicinal chemistry , reactivity (psychology) , carbocation , silylation , lewis acids and bases , stereochemistry , reagent , pnictogen , organic chemistry , catalysis , medicine , physics , alternative medicine , superconductivity , pathology , quantum mechanics
The reaction of the carbonyl‐functionalized phosphaalkenes RC(O)P=C(NMe 2 ) 2 [R = t Bu ( 2a ), Ph ( 2b )] with protic acids and alkylating reagents occurred at the two‐coordinate phosphorus atom to give the phosphanyl‐substituted carbocations 3a,b and 4a,b . In contrast, treatment with Me 3 SiOSO 2 CF 3 resulted in attack at the oxygen atom by the silyl group, and the formation of [RC(OSiMe 3 )=PC(NMe 2 ) 2 ]SO 3 CF 3 ( 5a,b ). Similarly, the Lewis acids B(C 6 F 5 ) 3 , Al( t Bu) 2 Cl and AlMe 3 were ligated to the oxygen atom of the carbonyl group. Two equivalents of GaMe 3 were added to the oxygen and phosphorus atom of the phosphaalkene to yield the thermolabile complexes [RC(OGaMe 3 )=P(GaMe 3 )C(NMe 2 ) 2 ] ( 10a,b ). In contrast, one molecule of InMe 3 was bound to the phosphorus center of the phosphorus compound. Reaction of the phosphaalkenes with [Ni(CO) 4 ], [Fe 2 (CO) 9 ] or [{( Z )‐cyclooctene}Cr(CO) 5 ] also took place at the pnictogen atom, resulting in complexes of the type [RC(O)P{M(CO) n }C(NMe 2 ) 2 ] (R = t Bu, Ph; M = Ni, n = 3; Fe, n = 4; Cr, n = 5). The chemical transformations reported here underline the versatile chemistry of phosphaalkenes and emphasize a relationship between carbonyl‐functionalized phosphaalkenes and the well‐investigated class of phosphorus ylides. X‐ray structures of compounds 6b , 7b* , 10a , 11a and 12a are reported.