[mnakhla]

I cant see a mechanism for carbenes attacking alkanes.,, ive only seen them reacting with alkenes and alkynes  to form cyclopropane rings and such... but i suspect that they being very reactive and unstable would possibly be able to attack an alkane...but i dont know so can I have a little help...does a carbene attack an alkane or an alcohol such as ch3ch2oh... i would think the alcohol would be more reactive..? the carbene im using will be generated from the reaction of Naoh and chcl3 ...so it will be dichlorocarbene....

any answers or ideas/corrections will be appreciated =D

[nj_bartel]

A heads up - although some textbooks use NaOH or KOH to form carbenes with chloroform, I've been told you need a significantly stronger base, such as sodium amide.

and

 http://en.wikipedia.org/wiki/Carbene

Lots of good reactivity info.

[Mitch]

Carbenes are actually good nucleophilles or electrophilles, they tend to swing both ways.

[mnakhla]

thanks that was actually very helpful... !....My O-chem professor said that chcl3 and Naoh does work..but if need be i have alkali metals sitting on the shelf as well so preparation of an amide will not be an issue =D

[shelanachium]

Some carbenes such as CH2 can insert into C-H bonds but CCl2 does not, because it is more stable than CH2. This is because p orbitals on Cl can overlap with the empty p orbital on C, stabilising the carbene and making it less reactive. The same goes for other dihalocarbenes and also those with N, O or S substituents. CCl2 will however react with alkenes to give cyclopropane derivatives as CH2 does.

[mnakhla]

thanks ! that explains alot actually...because i ironically enough was just thinking about the relative stablities of the different carbenes while walking around campus today and couldnt decide whether the chlorocarbenes would be more or less stable then the ch2 carbenes,...my thinking though was that the chlorines being electron with drawing would destabalize the molecule even further...but your answer makes sense  thanks =D