First examples of oxaphosphirane pentacarbonylchromium(0) and -molybdenum(0) complexes: synthesis, structures and reactions

Abstract

Synthesis of the first oxaphosphirane chromium(0) and molybdenum(0) complexes of the type [{(R(1)PCH(R(2))-O}M(CO)(5)] (R(1) = C(5)Me(5)) (8a-e, 15a-e) and (R(1) = CH(SiMe(3))(2)) (9a-e, 16a-e) via reaction of dichloro(organo)- (1, 2, 10, 11) and chloro(organo)phosphane complexes (3,4,12) with lithium bases and aldehydes 7a-e is reported. Furthermore, bicyclic 1,3-oxaphospholane complexes 17 and 18 have been obtained via O-protonation of oxaphosphirane complexes 8a and 15a with HCl. All complexes were characterized by NMR, IR spectroscopic, mass spectrometric investigations and, in addition, single-crystal X-ray structures of complexes 8a-e, 9a,c, 15a,b,e, 16a-c, 17, 18 are presented and discussed.

Reactions of Li/Cl Phosphinidenoid Complexes with 1,3,4,5‐Tetramethylimidazol‐2‐ylidene: A New Route to N‐Heterocyclic Carbene Adducts of Terminal Phosphin­idene Complexes and an Unprecedented Transformation of an Oxaphosphirane Complex

“…Because follow‐up reactions of the formed oxaphosphirane complex 9 with 3 could not be excluded under the conditions described above, we examined the stability and reactivity of oxaphosphirane complex 10 10c,20 towards 3 in THF (Scheme ). Surprisingly, quantitative conversion of oxaphosphirane complex 10 yielded complex 4 .…”

Cycloaddition of P−C Single Bonds: Stereoselective Formation of Benzo‐1,3,6,2‐trioxaphosphepine Complexes via a Ditopic van der Waals Complex

“…In contrast, tetrachloro‐ ortho ‐benzoquinone (TOB or o ‐chloranil) reacted readily to yield complex 2 c , which possesses a medium‐sized, novel heterocyclic P ligand, the benzo‐1,3,6,2‐trioxaphosphepine. The transferability of this reaction was tested with the molybdenum ( 1 b ) and chromium complexes ( 1 a ), but only in the case of the molybdenum complex ( 1 b ) was the product ( 2 b ) formed (Scheme ). In addition, we studied the oxaphosphirane complex 1 d with a C 5 Me 5 group as the P‐substituent, which could possibly interfere because of its π‐system.…”

Synthesis of Li/OR phosphinidenoid complexes: on the evidence for intramolecular O–Li donation and the effect of cation encapsulation

“…for the starting dichloro(organo)phosphane complexes 6-10 or oxaphosphirane complexes. 8 The molecular structures of 12a,b, 13b, 14a-c, 15a and 16a (Fig. 2-5) were determined for the solid state by single-crystal X-ray diffraction studies (for the structures 12a, 14c, 15a and 16a see ESI †).…”