P2P

[obituary]

Yes, obit is trying yet again for the new synth.  now please say something and give refs if this has been seen before.  obit knows that (believe it was) Rev. drone proposed a phenyllithium and bromoacetone synth for P2P.

does it work?  (side question)

on to the new synth possibility:

triphenylborane + bromoacetone -(OH^-)-> P2P

this seems very reasonable considering that alkylboranes will react with bromo-keto comps to give ketones under basic conditions

how available is triphenylborane?

[obituary]

somebody?

[PrimoPyro]

i dunno about the theory, but as for availability:

triphenylborane: (C6H5)3B   CAS# 960-71-4
Crystalline, m.p. 147 deg C   b.p. 208 deg C/14mm

97.8% assay:  1g  $17.50  5g $63.90   25g $278

from a wellknown global chemical manufacturer....
Of COURSE we don't know what we're doing! That's why it's called research!  (boom...)    

[jim]

There is no reason why the enolate synhtesis shouldn't work.

I don't know about the borane synthesis however...

[obituary]

the only possible reason obit has found why the borane synth won't work is that the borane is directly attached to an aromatic.  at the same time, obit doesn't think that it makes a difference in this case.  it might if there were substitutions on the ring, but there aren't.   does anybody have a way to try this small scale/lab research on precursors, coughRHODIUMcough.  damn cold.

[lugh]

These borane syntheses and the related nitrile syntheses are old and well known to many. Some other related refs are JACS 90: 5280,5936 & 6891 (1968) & 91: 4304, 6852 & 6854 Diazoeacetone can be used as an alternative to bromoacetone. They work very well with the substituted aromatics. While not the cheapest, these routes offer the advantage of being generally applicable, and thus very suited for our purposes.

[Rhodium]

Here are all the references listed in

Post 204789

(lugh: "Re: P2P", Novel Discourse) for the synthesis of different alkylboranes, as well as their further manipulation to ketones (like P2P/MDP2P). Check out the last two in particular if all of these articles overwhelm you.

Cyclic hydroboration of 1,5-cyclooctadiene. A simple synthesis of 9-borabicyclo[3.3.1]nonane, an unusually stable dialkylborane
Evord F. Knights, Herbert C. Brown

J. Am. Chem. Soc. 90(19), 5280-5281 (1968)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/organoborane2ketone-1.pdf)

The reaction of trialkylboranes with diazoacetone. A new ketone synthesis
John Hooz, Siegfried Linke

J. Am. Chem. Soc. 90(21), 5936-5937 (1968)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/organoborane2ketone-2.pdf)

Alkylation of diazoacetonitrile and ethyl diazoacetate by organoboranes. Synthesis of nitriles and esters
John Hooz, Siegfried Linke

J. Am. Chem. Soc. 90(24), 6891-6892 (1968)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/organoborane2ketone-3.pdf)

Reaction of ethyl haloacetates and .alpha.-bromo ketones with B-aryl-9-borabicyclo(3.3.1)nonanes under the influence of potassium tert-butoxide. A new convenient procedure for the .alpha.-arylation of ketones and esters
Herbert Charles Brown, Milorad M. Rogic

J. Am. Chem. Soc. 91(15), 4304-4305 (1969)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/organoborane2ketone-4.pdf)

Reaction of organoboranes with bromoacetone under the influence of potassium 2,6-Di-tert-butylphenoxide.
A convenient procedure for the conversion of olefins into methyl ketones via hydroboration
Herbert Charles Brown, Hirohiko Nambu, Milorad M. Rogic

J. Am. Chem. Soc. 91(24), 6852-6854 (1969)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/organoborane2ketone-5.pdf)

Reaction of organoboranes with chloroacetonitrile under the influence of potassium 2,6-Di-tert-butylphenoxide.
A convenient procedure for the conversion of olefins into nitriles via hydroboration
Herbert Charles Brown, Hirohiko Nambu, Milorad M. Rogic

J. Am. Chem. Soc. 91(24), 6854-6855 (1969)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/organoborane2ketone-6.pdf)