Platinum complexes cyclopropene

Direct metallacyclobutene formation by reaction of free tetrafluorocyclopropene and trigonal platinum complexes or tetragonal iridium complexes (equation 230) is also reported in the literature. These reactions may proceed via a labile / -cyclopropene complex intermediate. However, the stereoselectivity observed in the product complexes of... 

The first cyclopropene transition metal complexes isolated were stable Pt(0) species, e.g. 296. These are obtained from the displacement of ethylene in various platinum complexes by cyclopropene and analogous Ni(0) complexes are now available The dominant bonding is of the 7r-type with the lengthened C(l)-C(2) bond reflecting a significant relief of strain upon complexation. Complex 296 liberates the cyclopropene upon treatment with carbon disulphide. 

Another route to p.-Carbido complexes which we have found is oxidative addition of Lalor s halocarbyne complexes [21] to zero valent triphenylphosphine compounds of nickel, palladium and platinum. In these reactions the heterodimetalla cyclopropenes could be isolated which isomerize at higher temperatures to the dimetalla allene complexes. The first adducts of arylcarbyne complexes to zerovalent platinum complexes (arylcarbyne as analogue of ace-... 

The addition of B pin to activated alkenes is an efficient way to generate alkylboronates. One version of this reaction entailed the use of a platinum complex to catalyze the addition, which generated remarkably high yields of the boronates when heated (Scheme 6.6) [12, 13]. While there was some substrate specificity, this was an effective approach to the synthesis of alkylboronate compounds from Michael acceptors. It should be noted that a chiral imidazolinium salt catalyzed the enantioselective borylation of acyclic enones with excellent selectivity (up to er=98 2 [ 14]). The copper-catalyzed borylation of cyclopropenes has also been reported using bisphosphine as the chiral ligand (Schanes 6.7 and 6.8) [15,16] in... 

Oxidative activation of cyclopropenes is much less frequently encountered. The reactions of various platinum(O) complexes with the electron-deficient methylenecyclopropene 170 affords platinacyclobutene complexes, as reported nearly 30 years ago <1978ICA19>. More recent investigation has established that in the presence of two or more equivalents of the metal, bicyclic diplatinum complexes can be generated (Scheme 40) <1996JBS75>. 

Platinum(0) complexes acetylides, 387 alkenes, 410 synthesis, 410 alkynes, 415 electrophilic attack, 416 NMR, 415 properties, 415 allenes, 412 cyclopropene, 411 haloalkenes reactions, 414... 

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