Germyl chloride

Crotonic esters and certain homologues, when converted to their enolates with LDA and treated with stannyl and germyl chlorides, afford the y-metallo derivatives (Table 10)57. In contrast, silylation of these enolates leads to the 0-silyl derivatives. Interestingly, the halostannane derivatives show a strong preference for the (Z) geometry suggestive of a donor-acceptor interaction between the carbonyl oxygen and the electropositive tin atom,... 

Acyl silanes753,804 8n and germanes812 can be prepared from MVL (524) or EVL (525) by reaction with silyl and germyl chlorides, respectively, followed by acid hydrolysis (Scheme 143). Vinyl stannanes are useful for the preparation of unsolvated MVL753,754... 

Treatment of the chloride 142a with 5% solution of KOH in methanol followed by neutralization with citric acid gave germanol MeC(0)N(Me)CH2GeMe20H. In the case of bis-germyl derivative 142d the product of heterocyclization 151 was obtained (equation 38)485. 

Bis(/i,-germyl)iron carbonyl complexes without a metal-metal bond were synthesized by the reaction of Fe(CO)5 with germanium tetrahalides and later by an alternate route involving high temperature reaction of Fe(CO)5 with a bis(halogermyl)iron carbonyl complex. Ferrous chloride is a byproduct of these reactions (equation 32)86-89. 

An example of double germylation was first discovered in the reaction of tricloroger-mane etherate with allyl chloride, as shown in equation 3076. Product 29 with two GeCl3 groups was obtained together with the product of condensation. 

The two compounds 62 and 63 were isolated and characterized. As in the previously described examples, methylation of the chlorides by MeMgBr proceeded smoothly without any side reactions in which germyl groups are split off. 

Arenetellurolates reacted with triphenyl germyl, stannyl, and plumbyl chlorides12 18, but not with triphenylsilyl chloride or triphenylmethyl chloride16 17. However, reactions of... 

Lithium ethanetellurolate condensed with silyl chlorides and with triethylgermyl chloride to form ethyl silyl (germyl) tellurium compounds6. 

Aminoethynylmetallation with reactive ketenes usually leads to mixtures of products because of competing [2 + 2]cycloadditions. Thus when only 68 are desired one will use the very common acid chlorides instead of ketenes. Stable silylated and germylated ketenes react only by [2 + 2] cycloaddition, 57). Aliphatic ketenes, isopropylidene and cyclopentylidene ketenes react more slowly and yields are low (114)156). 

Ynol tosylates are synthesized from terminal alkynes via a unique sequence (equation 10). The hypervalent organoiodine compound 32, prepared by treatment of iodosoben-zene diacetate with /i-toluenesulfonic acid, reacts with the terminal alkynes 31 to give the iodonium tosylates 33, which are then treated with 10 mol% of CuOTf or AgOTf to afford the ynol tosylates 34. Finally, the ynol tosylates 34 are converted into lithium ynolates 35 by treatment with MeLi. The ynolates are trapped with r-butyldimethylsilyl chloride, triethylgermyl chloride and tributylstannyl chloride to give the silyl ynol ethers 36, the germyl ketenes 37 and the stannyl ketene 38. ... 

A recent example of the preparation of a silylated and germylated cyclopropanone has been provided by Russian workers who added diazomethane in ether or methylene chloride at —130 °C to an equimolar amount of trimethylsilyl and trimethylgermylketene. The authors were able to obtain PMR spectra of the parent ketones which show an ABC system of cyclopropane ring protons at 0.8-1.8 ppm. These products react with methanol to form hemiketals and undergo ring expansion with excess diazomethane to form the corresponding cyclobutanone derivatives. 

Lithium alkanetellurolates, prepared from tellurium and an alkyl lithium compound or dialkyl ditellurium derivatives and hthium, and sodium arenetellurolates, obtained from diaryl ditellurium compounds and sodium borohydride ", reacted with triorganosilyl, -germyl, -stannyl, and -plumbyl chlorides to produce, for instance, organo triorganosilyl tellurium compounds. 

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