Wikipedia:Featured article candidates/Asymmetric hydrogenation/archive1


 * The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was not promoted by GrahamColm 13:32, 1 December 2012.

Asymmetric hydrogenation

 * Nominator(s): Bmalbrecht (talk) 14:06, 27 November 2012 (UTC)

I am nominating this for featured article because I believe that it is of a similar quality to other featured articles addressing topics in the same field (chemistry). It has undergone peer review by editors with and without strong chemical backgrounds and adjustments have been made to make it as approachable as possible to the non-chemist while still providing enough substance to be useful. I believe that all important aspects of the field have been covered, including areas of modern interest, and that the article is essentially complete. It is thoroughly referenced, clearly written, and is intended to be without bias. In short, I believe it meets all requirements for featured article status. Bmalbrecht (talk) 14:06, 27 November 2012 (UTC)

Bmalbrecht (talk) 14:21, 27 November 2012 (UTC)
 * For comments in the chemistry project, in response to which I am also doing some edits, please see follow this link.
 * Promising article and truly impressive knowledge, but the article suffers from excessive reliance on primary sources. Artwork needs to be made less ugly. --Smokefoot (talk) 15:06, 27 November 2012 (UTC)


 *  Oppose Drive-by comments from Jim Article hasn't been to GA, and the peer review was one paragraph from one editor. Even without reading the main text, just the lead, there are some worrying signs  Jimfbleak  -  talk to me?  15:51, 27 November 2012 (UTC)
 * Lead section doesn't summarise article WP:LEAD
 * First achieved with a heterogeneous palladium catalyst deposited on silk &mdash; seems to be the entire history of assymetric catalysis, and even that isn't mentioned in the main text.
 * Headings and captions don't conform to MoS
 * Quadrant Model for Asymmetric Hydrogenation? also at least two headings and a caption.  Jimfbleak -  talk to me?  07:05, 29 November 2012 (UTC)
 * That example fixed, as were various others. Bmalbrecht (talk) 15:04, 29 November 2012 (UTC)
 * pov in lead, "flourished","remarkable"
 * Shouldn't be refs in lead
 * What is Wade ref doing?
 * Why are the refs not numbered?
 * There are non-alphanumeric symbols in the refs
 * see ref 32  Jimfbleak -  talk to me?  07:05, 29 November 2012 (UTC)
 * Oops. That one is now fixed too. Bmalbrecht (talk) 12:50, 29 November 2012 (UTC)
 * There are eight repeated links in the main text, excluding lead and captions
 * The thought behind this is that readers are likely to skip to the sections that are most interesting to them rather than reading the whole article. If that's true, then linking up each section individually allows readers easier access to relevant information. Bmalbrecht (talk) 13:28, 28 November 2012 (UTC)
 * Why are the last two refs rolled into
 * Over-reliance on primary sources, no mention of secondary sources such as Caprio and Williams (2009)Catalysis in Asymmetric Synthesis or Ralph (2007)  Immobilization of homogeneous asymmetric hydrogenation catalysts
 * heterogeneous palladium catalyst &mdash; first line is hardly welcoming with three consecutive unlinked and unexplained technical terms
 * I'm surprised there is no link to Enantioselective synthesis
 * A minute on Google found this long full-text article, not even mentioned in your article.

Responses to Jimfbleak's remarks:
 * The peer review actually happened from numerous people, but only one chose to comment on the peer review page itself. Others wrote on the WikiProject Chemistry site, on their own talk pages, in personal emails to me, etc.  Comments were highly positive to the extent that going through GA then FA nomination process seemed unnecessary, especially when it is not required.
 * I tried to moderate the language in the lead somewhat. The use of some "technical" terms is inevitable but I would expect a someone with a pre-university education in chemistry to be able to follow along.  An effort at improved summary was also made.
 * The palladium on silk is not mentioned in the text because it is essentially an interesting bit of trivia, something to peak your interest. It is not generally discussed within the modern field and did not clearly contribute to any of the advancements in homogeneous catalysis (where nearly all the work is done).  Further history is mentioned within the text, though there is no history section.  I found that it worked better this way (early editions did have a history section) though if there is consensus that this is a problem I could try to add one.
 * Well, the title of the article isn't "Modern homogenous asymmetric_hydrogenation". If this is part of the history of the topic, it should be mentioned in the main text, and I'm astonished that, if your article is to be believed, that it is the only known heterogeneous reaction leading to asymmetric hydrogenation. If that is not the case, you either need to include hetergeneous catalysis or move your article to a more appropriate title. I'm not bothered whether there is an actual history section, just if the article is doing what it (currently) says on the tin  Jimfbleak -  talk to me?  07:34, 28 November 2012 (UTC)
 * On consideration, I agree. I will need to take some time to put it together but including it is not unreasonable and within the declared purview of the article Bmalbrecht (talk) 13:51, 28 November 2012 (UTC)
 * The point of view in the lead seems reasonable to me. There are published works out there that say that hydrogenation is without a doubt the most important process of the modern era (with the implication that the asymmetric version is therefore of like importance).  I stay well back from that extreme but the technology does deserve credit.  For a reaction to work as well and as consistently as it does is rare.  Like the text says, it can literally give results as good as what enzymes give, a claim that almost no other chemical transformation can match.
 * The use of refs in the lead is an established practice in other FA chemistry articles. It is also largely necessary, since the scientific community would frown upon reference to anyone's work without citation.
 * I have no idea what has happened to the references. They definitely had numbers in recent times (and you can still see the matching numbers in the text).  I will attempt to fix this.
 * I don't know what you mean about the roll in. I would say that they are in the reflist because I want to cite them...
 * What I mean is that you have formatted them as part of the reflist template  I've never seen that before, why aren't they formatted like normal refs?  Jimfbleak  -  talk to me?  07:37, 28 November 2012 (UTC)
 * Headings and captions now conform to MoS
 * The issue of secondary sources is again something of a conflict between how Wikipedia wishes to do things and how the chemical community wishes to do things. I have generally defaulted to favouring the chemist's preference since it is their work (again, see the Aldol reaction for an FA precedent in choosing to do this. (There are a handful secondary references, though I understand why finding them in all the primary ones would be difficult).
 * I would be happy to link to [[Enantioselective synthesis] if I could find a place where it made sense to do so. It might be logical to add in a "use in total synthesis" section where I could make such a link.  Thoughts?
 * There are literally thousands of works in this area that I have not cited that can likely be found by Google. To attempt to include them all would be futile as would attempting to include some mention of all the work ever done in the area.

Bmalbrecht (talk) 01:35, 28 November 2012 (UTC)
 * I've withdrawn my oppose for now, but I'll hold off doing a full review util I see other comments on style issues, and I'm still unhappy about the lead section and referencing problems. You may have to reformat the refs with non-alphanumeric characters using the cite journal template instead of cite doi  Jimfbleak -  talk to me?  07:37, 28 November 2012 (UTC)
 * I've fixed the reference issues now. Bmalbrecht (talk) 13:28, 28 November 2012 (UTC)
 * Please note that you shouldn't strike reviewers' comments yourself. It is for the reviewer to decide if your response has addressed the query, even on minor points. Just indicate that you have taken the action, and leave it to the reviewer to decide. I know you acted in good faith, but it actually makes it harder for the reviewer to keep track  Jimfbleak -  talk to me?  06:57, 29 November 2012 (UTC)
 * ...and in fact I've unstruck two because I'm not satisfied that the issues have been fully sorted  Jimfbleak - </b> talk to me?  07:05, 29 November 2012 (UTC)


 * Oppose per prose issues. I only read the first two sentences but I already hate "First achieved with a heterogeneous palladium catalyst deposited on silk,[1] this field..." How can we achieve a field? What's an unsaturated bond? I will read the rest of the article but if it's all as bad as this it wouldn't even meet GA standard. Sorry. --MarchOrDie (talk) 06:41, 29 November 2012 (UTC)
 * Oppose - There are too many issues, most of which have been listed above by Jim. The article would benefit from a much better peer review and a stab at GAC, before coming here.  Driving via this route would eradicate a lot of the current problems the article has. --   Cassianto <sup style="font-family:Papyrus;">Talk   08:40, 29 November 2012 (UTC)
 * Serious Doubts - Bmalbrecht, I know that the FAC process is difficult the first time and I know that some of the FAC requirements seem in conflict with scientific practice, but as this is an encyclopedia and not a scientific paper, I advise you that it is necessary to adapt. I am the principal author of one of wikipedia's FA-level chemistry articles, I found the FAC process a real challenge, and I encourage you to keep trying.  Unfortunately, I have to agree with others that this article needs a lot of work.  I'm going to provide a non-exhaustive list of issues that I see, in hopes they will help you to improve the article.
 * First sentence: The first sentence reads "In organic chemistry, asymmetric hydrogenation is a chemical process that adds a molecule of hydrogen to one face of an unsaturated bond."  To understand this, a reader must know that "add" refers to an addition reaction, yet there is no even a wikilink to indicate the word "add" is being used in a technical way.  Further, ethylene has an unsaturated bond, hence by this definition hydrogenation of ethylene is asymmetric hydrogenation, yet it is not.  Have a look at the hydrogenation article - which is also not wikilinked - to see a less technical description of a process.  Maybe "Asymmetric hydrogenation is an addition reaction between molecular hydrogen (H2) and an unsaturated organic compound in which one or more new and desired elements of chirality are selectively synthesised."  This could be referenced to doi:10.1351/goldbook.A00484 (the IUPAC Compendium of Chemical Technology).  I would accompany the first paragraph with an image of a simple asymmetric hydrogenation, such as the top part of the image Noyoriintro.png showing the reduction of ethyl 3-oxobutanoate on the Noyori asymmetric hydrogenation page.  Incidentally, that page and this will overlap, but this article should still briefly describe the Nobel Prize winning work, probably in its own section with a 'for more information' link at the top of that section.
 * Second sentence: The second sentence reads "A more specific technical definition could term it as the hydrogenation of prochiral substrates to preferentially produce one of two chiral products."  FA standards mention prose quality approaching brilliant; unfortunately, this sentence is awkward.  One of two chiral products is also questionable, in that if two chiral centres are proiduced there are theoretically four stereoisomers possible.
 * Third sentence: The third sentence reads "First achieved with a heterogeneous palladium catalyst deposited on silk, this field has since flourished predominantly in the realm of homogeneous catalysis." It does not make sense as "the field" is what is first achieved, but I suspect "first achieved" is meant to refer to asymmetric hydrogenation.  I could go on, but basically the lead needs re-writing.
 * Article structure: The article should stand on its own without the lead (which is a summary) so the article needs to start with explaining what asymmetric hydrogenation is, possibly followed by history, before getting to mechanism.
 * Mechanism: The prose again assumes considerable knowledge of organometallic chemistry.  The side-by-side mechanisms make seeing the differences and similarities very difficult.  A single diagram where the active catalyst is show to associate the olefin on one side and oxidatively add the hydrogen on the other, coming together to a common olefin-dihydride-rhodium(III) species (each side clearly labelled) would show the differences, and that the rest of the catalytic cycle is the same.  After the diagram, the "sense of stereochemistry" sentence is unclear - does this mean that the stereochemical outcome can be predicted and understood in terms of steric interactions?
 * Quadrant model image: This image needs correction.  [RhHX(PPh2)2] would be incredibly unstable as the phosphine ligands are short one substituent.  Do you mean PPh3?
 * Historically important diphosphine ligands image: This image has labels for the ligands with stereochemical descriptors.  (R) and (S) should always be italicised in print and underlined when handwritten.  This is a mistake in other images too.
 * Highly effective system for the asymmetric hydrogenation of ketones image: The '2' in [Ir(cod)Cl]2 dimer should be a subscript, and this is another case of italicised R's needed.
 * Asymmetric hydrogenation of pyridines image: What happens to the 5-member ring substituent in the starting material?
 * Sequential alkylation and asymmetric hydrogenation of 2-substituted indoles image: The R1 substituent on the phenyl ring of the starting material becomes an R substituent in the product.  The R2 substituent in the starting material becomes an R1 substituent in the product.  An R1 substituent on the nitrogen heterocycle ring is introduced in the product, yet the R3 substituent on the aldehyde starting material vanishes completely.
 * Ok, that's enough for now. Good luck.  EdChem (talk) 12:47, 1 December 2012 (UTC)

Delegate's closing comment - There are too many issues to resolve in a reasonable time here.


 * The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.