Reactions of a Chelated Cyclopentadienylcobalt(I) Complex with 3,3-Disubstituted Cyclopropenes:  Formation of Isoprene, Vinylcarbene, and 1-Phosphadiene Ligands at the Metal

Abstract

(Di-tert-butylphosphanyl-P-ethyl)cyclopentadienylcobalt(I) complexes 1 and 2 were treated with 3,3-disubstituted cyclopropenes to give isoprene and vinylcarbene complexes. The diphenylvinylcarbene complex reacted with tert-butylphosphaethyne to give unusual coupling products.

The First Late‐Transition‐Metal Cyclopentadienyl Chelate Complexes with Silylphosphane or Secondary Phosphane Tethers

“…The respective ligand system is generated by nucleophilic opening of spiro[2.4]hepta-4,6diene with lithium tert-butylphosphide. Cyclopentadienyl chelate complexes with anionic tethers.In the context of our interest in cyclopentadienylalkylphosphane chelates of late-transition-metals such as cobalt [17][18][19][20][21][22][23][24][25][26][27][28][29] and nickel, [11,13] we noticed that phosphido chelates such as 9 are comparatively rare and known only for early-transition-metals such as group 4 metals, [15,[30][31][32][33] lanthanides, [34] or niobium. Treatment of lithium tert-butylphosphide with tert-butylchlorodimethylsilane or with chlorotriisopropylsilane affords the respective secondary silylphosphanes.…”

Syntheses and Structures of Sterically Congested Linear and Branched Cobalta[n]triangulanes

“…This behavior is in contrast to that of related cyclopropene-derived complexes. [25] In the current complexes, the coordinated double bonds undergo a significant out-of-plane bending, thus, these complexes are more suit-A C H T U N G T R E N N U N G ably described as cobalta j n]triangulanes rather than as alkene complexes.…”

The broad diversity of CpCo(I) complexes

“…Its reaction with various alkynes (see also 3.4, Scheme 27) and the Brought to you by | Carleton University OCUL Authenticated Download Date | 6/23/15 1:34 AM different chelating ligands such as 2,2′-bipyridine and cod has been described in detail (Foerstner et al 1996a). Later on, Butenschön reported on the substitution of the ethene ligand in 65 with cyclopropene derivatives yielding compounds 66 and 67 (Foerstner et al 1998). The activation barrier of the insertion of the Co(I) center into one of the strained C-C single bonds of the cyclopropene leading to a formation of a cobaltacyclobutene depends on the substituents on the cyclopropene.…”