Pyridine chromium pentacarbonyl

Bis(] J-dimethylethyl) pyridine)tin]pentacarbonyl-chromium, 9CI. [ Pyridine)diAcrUbutylstannanediyl]-pentacarbonylchromi um [50982-07-5]... 

Similarly, the pentacarbonyl[(2-cyclopropyl-2-dimethylaminovinyl)ethoxycarbene]chromium complex 27, prepared from pentacarbonyl[cyclopropylethynyl(ethoxy)carbene]chromium 19 and dimethylamine (or other secondary amines), reacted with pent-l-yne or phenylethyne to give 1-propyl- or 1-phenyl-substituted 5-cyclopropyl-5-dimethylamino-3-ethoxycyclopenta-1,3-diene in 62-77% yield.With substituents other than cyclopropyl yields were drastically lower unless the reaction of the carbene complex was performed in pyridine or acetonitrile. 

Pentacarbonyl(carbene)chromium complexes with a primary amino group at the alkenyl terminus 32, readily obtained by addition of ammonia to alkynyl-substituted complexes, initially rearranged upon heating to pentacarbonylchromium-coordinated 1-azabuta-l,3-dienes 33, which subsequently underwent [4 + 2] cycloaddition of an alkyne to give coordinated 4-ethoxy-1,4-dihydropyridines the corresponding pyridines, e.g. 34, were formed by 1,4-elimination of ethanol. ... 

In the context of the anionic polymerization of CA derivatives, as considered in Section 10.3.2.2.1, it is notable that the polymerization of cyanoacrylates is also photoinitiated by substituted pyridine pentacarbonyl complexes of tungsten or chromium, i.e. M(CO)5L with M = Cr or W, and L = 2- or 4-vinylpyridine [60]. Photo-released pyridine adds to CA, and the resulting zwitterion initiates the anionic chain polymerization (see Scheme 10.16). 

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