You are free to be hopeful about the inevitability of some eventual discovery of a wholly adequate enantiomer concentrating mechanism. Just as I am free to conclude such a prospect has essentially zero probability. What would drive such a process on when at any intermediate stage the hoped for protein is wrecked because of random chirality? Teleology creeping in?
Obviously we come to very different conclusions from the same Tour exposition.
He never pretends to be an abiogenesis researcher but argues his synthetic chemistry training gives him a unique perspective biologists tend to trivialize - of just how many tightly controlled steps are needed to get a given outcome. Itself producing just one intermediate chemical species, within a prebiotic environment where as he puts it, 'time is not your friend'. To accuse him of being a charlatan is imo misguided at best.
You earlier claimed his long discussion of constructing a working nano-machine in an earlier article was a waste of time and irrelevant to abiogenesis.
To me you have entirely missed what he was trying to point out. That the huge multi-disciplinary intelligently manipulated trial and error effort required to finally get a working nano-car was child's play alongside the daunting complexity of even the simplest biological life. Which had to arise in a sparse environment with zero intelligent guidance according to mainstream position. One is then naturally led to ask some hard questions - imo.
Ah, so it was Tour claiming it was "nowhere good enough".
The nano-machine business is
utterly irrelevant. Life had several hundred million years in which to arise. The fact that this guy thinks he can't do it in his lab tells us precisely zero.
I'm afraid all these objections are just a variant of the Argument from Personal Incredulity: you and Tour can't see how it could have happened naturally - ergo it couldn't. That's not science. It's the God (or "Designer") of the Gaps.
It's a hard problem in science. everyone acknowledges that. But just because we can't see the answer today doesn't mean there is no answer, especially when you consider the huge progress that is occurring in abiogenesis research. Here is just one recent finding (I quote a tutorial from another forum I belong to). It is a beautiful example of why thinking about it the way Tour does, as a synthetic organic chemist, is completely unhelpful:
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Let us look at the unit of RNA.
The picture above shows a DNA and a RNA unit. They are very similar and consists of three parts
1) A
nucleobase (the one with lots of N i.e. Nitrogen groups). In the above picture the nucleobase is Guanine, the (G) of the ATCG letter system. There are 4 others with somewhat different structures.
2) The central cyclic pentagonal structure with the O atom at the crown. That is the
ribose sugar.
3) Finally the
Phosphate group (with phosphorus P in the middle) that acts as a bridge linking the different units in a long chain.
Now the question is how do you make this reasonably complicated molecule naturally?
For
40 years nobody could do it, and it is instructive to see why.
1)We have 3 distinct groups and every chemist who looks at it would think that the best way to
design such a thing is to make the 3 groups separately and join them together.
2)Unfortunately for chemists (like me),
Nature is not a designer and does not have foresight. Nature does not go about thinking "
I must synthesize X-Y-Z at the end; so let me make X then Y and then Z and then paste them together like the proper intelligent designer I am. " Nature, always goes through the
path of least resistance, i.e. the path that requires the least amount of energy. And that path is often not how humans would think is logical.
3)Thus all efforts by chemists for 40 years to make phosphate, ribose sugar and nucleobase separately and then join them together resulted in useless mess of all sorts of undesirable compounds.
This went on till 2009 (with creationists referring to this failure in glee) when a group in UK (Sutherland group, Cambridge) decided to
mix up nitrogen and oxygen chemistry and try to create a sugar-base hybrid in presence of phosphates from the very beginning.
And lo and behold, the entire reaction happened quickly and efficiently and created the RNA cytosine and RNA uracil units in just 5 steps and extremely efficiently!
What starting compounds do we need? They are very simple if completely bonkers:-
1) Hydrogen Cyanide (HCN) that most poisonous of all gases turns out to be the prime ingredient. HCN is found to form quite a bit in the oxygen poor CO2-N2 rich early atmosphere of earth when high impact meteors and comets were striking early earth.
2) Formaldehyde (HCHO) and acetylene (C2H2) the simplest of hydrocarbons also created in the atmosphere of early earth by photolysis of CO2 and H2O by the UV radiation of the sun (no ozone layer then) .
3) Hydrogen Sulphide (H2S), the most ubiquitous gas coming out of volcanoes with the smell of rotten eggs. And ancient earth was much more geologically active.
4) Water soluble phosphate that was leaching out of the iron-nickle meteors and comets that were falling to earth every month in those ancient times.
5) Copper and Zinc minerals, widely present in earth, as catalysts.
6) Lots of UV rays (no ozone layer then)
7) Periodic wet and dry conditions with temperatures ranging from 40 C - 5 C, very normal even for early earth.
Under these simple conditions Hydrogen Cynaide reacts with formaldehyde in the presence of H2S and and Copper salts to produce two simple sugars:- Glycolaldehyde (CHO-CH2-OH) and Glyceraldehyde (CHO-CH(OH)-CH2-OH) along with ammonia (NH3) .
Next Hydrogen Cyanide reacts sequentially with the two sugars above in presence of phosphate as catalyst at 40 C(like sodium phosphate) to create Nitogen-Oxygen hybrid ring structures called oxazoles. These oxazoles crystallize out of the water mixture on slight cooling.
(carbon atoms are at the vertices of the pentagon).
These oxazoles then react with cyanoacetylene (a compound formed by HCN reacting with C2H2) in the presence of phosphate and UV rays to directly create the RNA cytosine and uracil base.
So very briefly
2HCN + simple sugars ⇒ Oxazoles (in presence of phosphates)
Oxazoles + Cyanoacetylene + Phosphate ⇒ RNA units
The full pathway is shown below for reference.
I think the example teaches several things:-
1) God of the gaps always fails. Even in 2007, the leaders of the prebiotic chemistry field were saying RNA synthesis was impossible . There should be a permanent ban of scientists saying that unless they can formulate a law of physics that supports his case. Just because you can't do it does not make it impossible.
2) Nature has no foresight. Economy of means ,not neat categorical planning, is the hallmark of natural phenomena. Who would have thought lethal hydrogen cyanide and sugar-base hybrid would be the means by which nature would go about creating the building blocks of life?
3) In nature, one does not have sterilized labs where only one or two compounds are present at one time. So the way forward is systems chemistry, where most of the reagents are concurrently present and influence the reaction steps through catalytic action.
I am ending with a brief talk by the lead author of the paper (which should be intelligible now 
) and the small fact that in the last 6 years the group has gone on to use those above simple reagents to construct in the lab a chemical reaction cascade that very simply and effectively produces 3 of the 5 RNA/DNA units, 12 of the 20 amino acids and the building blocks of all lipid cell membranes. Thus now its an established fact that 70% of all the basic building blocks that life needs for its RNA-DNA-proteins and cell walls can be easily formed at one go in the prebiotic conditions of the early earth even before any evolution. They can now be created in a space of two days in a beaker with a little heating and cooling and a UV lamp once the way of thinking about how to go about the process changed.
Here is the full cascade. Its beautiful but would take me a month to explain. The snippet I tried explaining here is the one with the blue arrows (2-3-5-7-9-10).
