Talk:Todd:Catalytic, Asymmetric Pictet-Spengler Reaction

Use this page for discussion. Preface questions/comments with initials. Reply to questions but don't delete the question. If things are resolved, move them to the "resolved" section at the bottom of the page.

General Things that Need Doing

1. Papers below need looking at - whether to include or not
2. More papers might be relevant. Can do citation searches on papers already included, or new searches.
3. Papers that are already in the review, and have been summarized, need checking (see Quality Control, below for what's needed)
4. Insert DOI link for any paper lacking them on this page, formatted like this: Stoeckigt and Waldmann Angew 2011

Some specific things that currently need doing:
1. Need examples of important bioactive molecules and commercial molecules, e.g. drugs, that can be made with the PS.
2. Intro needs polishing off.

Small things that are needed:
1. Can anyone source a translation of the original Pictet-Spengler article? 10.1002/cber.19110440309. MHT - would be nice to see exactly how it is described there, yes. KAB - translation in progress!

Please don't use email if at all possible. Use this page or some other public forum. Remember if you want to contribute you are going to need an account on OWW and one on Mendeley where we are collecting citations. There is a shared Dropbox folder for access to all Chemdraw files and PDFs - for access contact Murray

General Comments, either on science or the review more broadly

Suggestions can go directly here or on the main page in italics. Minor comments can go in the sandbox area below.

1. Length: the page is quite long, but easier to leave as-is than split the page.
2. Molecule numbering: will happen at the end of the writing process.
3. Yield/ee terminology: Very high = 90+, high = 80+, good = 70+, moderate = 60+.
4. Plagiarism: make sure that no phrases are ever lifted directly from any paper.
5. Inserting schemes: On any page, on the left panel, under tool-box, you will need to select "Upload File." From there you upload the .png file from your computer. Copy the name of the file when it's uploaded (If you're unsure of the file naming convention, click anyone of the scheme .png's and it'll have the details there). Be careful if your file has the same name as an existing one - consider using a different name. Once you've uploaded the file you just need to edit the page where you'd like it to appear. Find the code for some previously uploaded scheme (doesn't matter which), copy and paste it to where you want to put your scheme, and just replace the name of the file you copied, with the name of your file that you just uploaded. Be careful to include .png and be careful of the spacing, there shouldn't be any within the file name. From there, just replace the title of the previous scheme with the details of your scheme. It's important that you only change the words and none of the punctuation that you may see in the code, e.g. "" or |. Just to check if it's alright, you may want to preview before you post. As always with wikis - use other peoples' examples.

MHT - Jan 21 - In the 2007 Hiemstra work, why does the sulfenyl help? Paper says should stabilize intermediate iminium ion and favour cyclization over competitive enamine formation) Paper gives: The use of N-sulfenyl substituents as protecting groups is known in peptide synthesis; see a) L. Zervas, D. Borovas, E. Gazis, J. Am. Chem. Soc. 1963, 85, 3660 – 3666 ; for reviews on sulfenamide chemistry, see b) F. A. Davis, U. K. Nadir, Org. Prep. Proced. Int. 1979, 11, 33–51; c)L. Craine, M. Raban, Chem. Rev. 1989, 89, 689 – 712 ; d) I. V. Koval, Russ. Chem. Rev. 1996, 65, 452 – 473.

MHT - Jan 22 - This paper is listed in the references, but has it been read and digested, to extract a) relevant info about the PS, but mainly b) mechanistic ideas of relevance? If not, leave the ref where it is, but add note in mech section about the need to include it there. Small-Molecule H-Bond Donors in Asymmetric Catalysis, A. G. Doyle and E. N. Jacobsen, Chem. Rev. 2007, 107, 5713-5743.

Appendices

Appendix 1

ILT - June 25 2016 - As it is difficult to construct very large schemes in Chemdraw I drew the substrate analogs for Appendix 1 in Chemdraw and then arranged them in Adobe Illustrator. The .pdf and .png files of the finished scheme are in Dropbox → Pictet-Spengler Review → Schemes → Appendices. I have also put all the relevant Chemdraw files in this folder as well.

Sandbox area for minor/temporary comments

This is the place to chat. Use initials for your comments/questions. Inactive chats/resolved things can be cut from here and pasted at the bottom of the page.

AEW- Feb 06 2013 - rather than having a separate mechanistic section can we include this in the relevant sections, saves repetition and might be clearer for readers. e.g. if you want to know about BA catalysed P-S reaction, its all in one place.

AEW- Feb 06 2013 - in a similar point, should there be a separate Natural products chapter?

AEW - Feb 03 2013 - In all cases, a single yield and ee are shown for a representative substrate from a paper. Is it not more useful to present a range of results to give a more accurate flavour of the paper being reviewed?

KAB - Jan22 - Added two .cdx files to DropBox under "All BINAP-derived" and "All Organocatalysts", with all the summarised papers' catalysts. MHT - good idea.

KAB - Jan22 - (not sure of relevancy) Found "Stereoselectivity of Superacid-Catalyzed Pictet−Spengler Cyclization Reactions." 2003 Ohwada OrgLett (added to DropBox). Proposes dicationic intermediate/transition state(?) mechanism for PS reaction of non-activated aromatics in the presence of catalytic (achiral) acid. MHT - sounds interesting, will check it out.

KAB - Feb11 - Significant discussion of PS mechanism and acid-base effects on non-enzymatic aq solution PS reactions with enzyme cat. reactions, using kinetic isotope effects. RDS appears to be the same for both systems. Discusses pH dependence of enzyme for catalysis but not binding of substrate. Also, proposal of enzyme mechanism with key Glu309, where tryptamine is deprotonated, increasing its nucleophilicity for aldehyde attack. Not sure of how (or if) this is to be spread between mech vs enzyme section?

MAT - Feb11 - KAB, I'm trying to nail down more of the enzymatic "practical uses" in the Enzymatic Catalysis section, but I moved my comment about the OpSTS computation TS to your mechs section. I think, as Mat mentioned, that the catalysis section has to be for actual end-products, so I'll likely write up the NCS generation of benzoisoquinoline nps and O'Connor / Stockigt's work with fluorinated tryptamines for my section.

Progress in 2016

ILT – June 27 2016 – Since April, 2016 I have been working on the enzymatic catalysis section. Using SciFinder I looked through all the papers to date that have cited Waldmann 2011 (10.1002/anie.201008071). I have included all relevant papers except the the ones listed on the Talk page under 'Enzymatic section'. These are the key papers for the subsection of the the review 'Expanding our Knowledge of the Pictet-Spenglerase Family'. They are grouped by enzyme.

I have added several papers under 'What is Known of the Mechanisms of Existing Systems' which I have come across while working on the enzyme and thiourea sections of the review. Although some of these papers have already been included in the review, there are sections within them which discuss mechanistic details which have not yet been covered.

In the enzymatic catalysis section I made three new subsections: Substrate Specificity, Rational Reengineering of Pictet-Spenglerases and Expanding our Knowledge of the Pictet-Spenglerase Family. I also created an Appendices heading and uploaded Appendix 1 - a complete (I think) scheme collating all the Pictet-Spenglerase substrate specificity data to date. This data is summarised in Scheme: (Substrate specificity for Pictet-Spenglerases).

ILT – Apr 10 2016 – Over the past month I conducted a thorough search for thiourea organocatalyst papers that have not yet been included. I did not find any area of research that has not already been covered. During my search I kept an eye out for other new organocatalysts but did not find anything of interest. I used the following research method:

Using SciFinder I searched for papers published between 2012 and March 2016 citing Jacobsen’s 2004 Paper (DOI: 10.1021/ja046259p) in which a chiral thiourea catalyst is used to promote an enantioselective Pictet-Spengler reaction for the first time. I searched for papers published since 2012 because I believe this is the last time someone focused on this section of the review.

I used the same method to look for more recent research by searching for papers citing Jacobsen’s latest 2011 work on thiourea-catalysed asymmetric Pictet-Spengler reactions (DOI: 10.1021/ol202300t).

I found several relevant reviews with brief sections devoted to elements covered in this review. I will mention these in a sentence or two towards the end of the introduction. In these reviews I did not find any thiourea research that has not already been included. As the most recent of these reviews was published in 2015, it supports my belief that there is no very obvious recent research that we have missed.

I now plan to turn my focus to the enzymatic catalysis section.

Specific Things That Need Doing

Introduction

• Need intro scheme containing structures for strychnine, morphine, vinblastine and reserpine and a scheme showing the synthesis of strictosidine from a PS reaction between tryptamine and secologanin. Combine with the existing structures of (-)-suaveoline and (-)-phalarine
• A number of small "needs" have been added to the intro section

'Quality Control

• Several "checks" still needed - essentially for accuracy of data and schemes, but stylistic points welcomed.

Papers that are relevant and need to be included for the first time

These papers are relevant and have not yet been included. They need a summary paragraph and possibly a scheme. Papers that are included need to have their citation data put in the right place in the review, and need to be added to the Mendeley Page. Papers that are not included should be listed in full in the "not-being used" section but do not need to be added to the Mendeley library.

• KAB: relevant. Early use of chiral phosphoric acids (binol and H8-binol) in enantioselective Morita-Baylis-Hillman reaction. N. T. McDougal, S. E. Schaus, J. Am. Chem. Soc. 2003, 125, 12094 (DOI: 10.1021/ja037705w) Paper MHT - that sounds very relevant - a year before Akiyama/Terada. Needs to be properly included? KAB Jan23 - Probably. It's a bit different to the rest. Acids were catalytic, but also required a "nucleophilic promotor." Not sure what that is, but it was present in less than stoich amounts as well. AEW - I'm not convinced that this paper is relevant for full inclusion. Should maybe be referenced but there are earlier examples of the use of chiral Bronsted acids...important to note that its not phosphoric acids as stated above but Binapthyl derived acids. Also, nothing strange about the nucleophilic promoter this is a requirement in M-B-H reactions - most frequently DABCO but can also be a phosphine (as in this case).

• ILT - June 27 2016 - Botta, 2016 10.2174/1381612822666151231100247 - Recent review of Pictet-Spengler reaction. Difficult to find paper so I put the pdf in the Dropbox 'PDFs' folder.

Papers that have not yet been included, but have been referenced by others

These papers need to be checked for relevance. They typically have come from other, relevant papers, but the relevance may not be clear. If they are relevant and need including, move the citation from this section to the "needs to be included" section above. If you wish to then actually include it in the review, write "your initials - doing" next to the paper and start working.

Introduction/Background to the PS Reaction

Early examples: probably rac/achiral

• Nature: Naoi, M.; Maruyama, W.; Nagy, G. M. Neurotoxicology 2004, 25, 193- 204 (DOI: 10.1016/S0161-813X(03)00099-8) Paper

Some good medicinal chemistry examples of isatin-derived compounds in Franz 2011 and bencivennia 2011.

Check for the importance of the structural motifs constructed with the reaction:

• Brown, R. T. In Indoles; Saxton, J. E., Ed.; Wiley- Interscience: New York, 1983; Part 4 (The Monoterpenoid Indole Alkaloids)
• Bentley, K. W. Nat. Prod. Rep. 2004, 21, 395-424 and references therein
• W. Jiang, J. Guan, M. J. Macielag, S. Zhang, Y. Qiu, P. Kraft, S. (DOI: 10.1021/jm025545d) Paper

Example chiral auxiliary approach: H. Waldmann, G. Schmidt, H. Henke, and M. Burkard, Angew. Chem. Int. Ed Engl., 1995, 34, 2401. as an example of an "easily removable" chiral aux not being too different from a chiral reagent? Referenced by Nakagawa.

Also possibly: Bhattacharjee, T. M. John, D. Haynes-Johnson, S. Lundeen, Z. Sui, J. Med. Chem. 2005, 48, 2126 – 2133 (DOI: 10.1021/jm0401098) Paper

Specifically with respect to carbolines:

• Kawasaki, T.; Higuchi, K. Nat. Prod. Rep. 2005, 22, 761–793 (DOI: 10.1039/B502162F) Paper
• Yu, J.; Wang, T.; Liu, X.; Deschamps, J.; Anderson, J. F.; Liao, X.; Cook, J. M. J. Org. Chem. 2003, 68, 7565–7581 (DOI: 10.1021/jo030006h) Paper
• Liao, X.; Zhou, H.; Yu, J.; Cook, J. M. J. Org. Chem. 2006, 71, 8884–8890 (DOI: 10.1021/jo061652u) Paper
• Ma, J.; Yin, W.; Zhou, H.; Cook, J. M. Org. Lett. 2007, 9, 3491–3494 (DOI: 10.1021/ol071220l) Paper
• Herraiz, T. J. Chromatogr. A 2000, 881, 483–499 (DOI: 10.1016/S0021-9673(99)01313-8) Paper
• Herraiz, T.; Galisteo, J.; Chamorro, C. J. Agric. Food Chem. 2003, 51, 2168–2173. (DOI: 10.1021/jf0210066) Paper Could cite - carbolines show antioxidant activity.

Diastereoselective examples:

Early diastereoselective, to reference: Ungemach, F.; DiPierro, M.; Weber, R.; Cook, J. M. J. Org. Chem. 1981, 46, 164. (DOI: 10.1021/jo00314a035) Paper

Study to reference: Cox, E. D.; Hamaker, L. K.; Li, J.; Yu, P.; Czerwinski, K. M.; Deng, L.; Bennett, D. W.; Cook, J. M. J. Org. Chem. 1997, 62, 44-61 (DOI: 10.1021/jo951170a) Paper.

To Do:

• Czarnocki, Z.; MacLean, D. B.; Szarek, W. A. Can. J. Chem. 1986, 64, 2205-2210. (DOI: 10.1139/v86-363) Paper
• Czarnocki, Z.; Suh, D.; MacLean, D. B.; Hultin, P. G.; Szarek, W. A. Can. J. Chem. 1992, 70, 1555-1561. (DOI: 10.1139/v92-191) Paper
• Czarnocki, Z.; Mieckzkowsi, J. B.; Kiegiel, J.; Arazn ́y, Z. Tetrahyedron: Asymmetry 1995, 6, 2899-2902. (DOI: 10.1016/0957-4166(95)00380-0) Paper

Papers relating to indole chemistry in asymmetric catalysis, cited by Bencivennia 2011:

• M. Bandini, A. Eicholtzer, Angew. Chem. Int. Ed. 2009, 48, 9608–9644
• G. Bartoli, G. Bencivenni, R. Dalpozzo, Chem. Soc. Rev. 2010, 39, 4449 – 4465
• T. B. Poulsen, K. A. Jørgensen, Chem. Rev. 2008, 108, 2903 – 2915
• E. MarquØs-López, R. P. Herrera, M. Christmann, Nat. Prod. Rep. 2010, 27, 1138 – 1167

Diastereoselective cited by Leighton: C. Bohlmann, R. Bohlmann, E. G. Rivera, C. Vogel, M. D. Manandhar, E. Winterfeldt, Liebigs Ann. Chem. 1985, 1752 R. Amann, D. Spitzner, Angew. Chem. 1991, 103, 1373; Angew. Chem. Int. Ed. Engl. 1991, 30, 1320 D. L. Comins, M. M. Badawi, Tetrahedron Lett. 1991, 32, 2995 H. Wald- mann, G. Schmidt, M. Jansen, J. Geb, Tetrahedron Lett. 1993, 34, 5867 H. Waldmann, G. Schmidt, M. Jansen, J. Geb, Tetrahedron 1994, 50, 11865 H. Waldmann, G. Schmidt, H. Henke, M. Burkard, Angew. Chem. 1995, 107, 2608; Angew. Chem. Int. Ed. Engl. 1995, 34, 2402 T. Soe, T. Kawate, N. Fukui, T. Hino, M. Nakagawa, Heterocycles 1996, 42, 347 T. Kawate, M. Yamanaka, M. Nakagawa, Heterocycles 1999, 50, 1033

Diastereoelective Reactions

First examples?

• Ungemach, F.; Soerens, D.; Weber, R.; DiPierro, M.; Campos ;Mokry, P.; Cook, J. M.; Silverton, J. V. J. Am. Chem. Soc. 1980,102,6976.

Diastereoselective (note: must be catalytic for full inclusion - may be no examples):

• Czarnocki, Z.; MacLean, D. B.; Szarek, W. A. Can. J. Chem. 1986, 64, 2205-2210. (DOI: 10.1139/v86-363) Paper
• Czarnocki, Z.; Suh, D.; MacLean, D. B.; Hultin, P. G.; Szarek, W. A. Can. J. Chem. 1992, 70, 1555-1561. (DOI: 10.1139/v92-191) Paper
• Czarnocki, Z.; Mieckzkowsi, J. B.; Kiegiel, J.; Arazn ́y, Z. Tetrahyedron: Asymmetry 1995, 6, 2899-2902. (DOI: 10.1016/0957-4166(95)00380-0) Paper

Lewis Acids

This section is done

Bronsted Acid Section

Akiyama (2004) says these earlier reports "claim" the use of chiral B acids - is that the case, and is the work relevant here?

• KAB: Not relevant. Not chiral acid, use of chiral aux. in Diels-Alder. C. Palomo, M. Oiarbide, J. M. Garcia, A. Gonzalez, A. Lecumberri, A. Linden, J. Am. Chem. Soc. 2002, 124, 10288 (DOI: 10.1021/ja025906e) Paper
• KAB: relevant. Early use of chiral phosphoric acids (binol and H8-binol) in enantioselective Morita-Baylis-Hillman reaction. N. T. McDougal, S. E. Schaus, J. Am. Chem. Soc. 2003, 125, 12094 (DOI: 10.1021/ja037705w) Paper MHT - that sounds very relevant - a year before Akiyama/Terada. Needs to be properly included? KAB Jan23 - Probably. It's a bit different to the rest. Acids were catalytic, but also required a "nucleophilic promotor." Not sure what that is, but it was present in less than stoich amounts as well.
• KAB: not quite relevant. Uses H-bond activation via chiral TADDOL, in highly enantioselective Hetero-Diels-Alder. Y. Huang, A. K. Unni, A. N. Thadani, V. H. Rawal, Nature 2003, 424, 146. MHT - sure, but why is this paper in Nature? What is it showing that is so important, and does this need to be mentioned in the mech section?

Akiyama (2004) also mentions these "metal salt" versions:

• J. Inanaga, Y. Sugimoto, T. Hanamoto, New J. Chem. 1995, 19, 707 (KAB: Can't access on usyd subscription)
• KAB: Hetero-DA asymmetric amplification by chiral Yb complexes. H. Furuno, T. Hanamoto, Y. Sugimoto, J. Inanaga, Org. Lett. 2000, 2, 49 (DOI: 10.1021/ol991189q) Paper

Previous Bronsted acid example from Terada

• KAB: Not relevent. Chiral TADDOL used in hetero-DA reaction - Huang, Y.; Unni, A. K.; Thadani, A. N.; Rawal, V. H. Nature 2003, 424, 146.
• KAB: See above - McDougal, N. T.; Schaus, S. E. J. Am. Chem. Soc. 2003,125, 12094.

Example of chiral charged Brønsted acid catalyst:

• Nugent, B. M.; Yoder, R. A.; Johnston, J. N. J. Am. Chem. Soc. 2004,126, 3418.

Jacobsen Strecker and Mannich history, from Terada

• Sigman, M. S.; Jacobsen, E. N. J. Am. Chem. Soc. 1998, 120, 4901.
• Vachal, P.; Jacobsen, E. N. Org. Lett. 2000, 2, 867.
• Sigman, M. S.; Vachal, P.; Jacobsen, E. N. Angew. Chem., Int. Ed. 2000, 39, 1279.
• Su, J. T.; Vachal, P.; Jacobsen, E. N. AdV. Synth. Catal. 2001, 343, 197.
• Vachal, P.; Jacobsen, E. N. J. Am. Chem. Soc. 2002, 124, 10013.
• Wenzel, A. G.; Lalonde, M. P.; Jacobsen, E. N. Synlett 2003, 1919.
• Wenzel, A. G.; Jacobsen, E. N. J. Am. Chem. Soc. 2002, 124, 12964.

See also:

• Okino, T.; Hoashi, Y.; Takemoto, Y. J. Am. Chem. Soc. 2003, 125, 12672.
• Okino, T.; Nakamura, S.; Furukawa, T.; Takemoto,Y. Org. Lett. 2004, 6, 625.

Copper complex example from Terada:

• Marigo, M.; Kjærsgaard, A.; Juhl, K.; Gathergood, N.; Jørgensen, K. A. Chem.- Eur. J. 2003, 9, 2359.

The strengths of these chiral phosphoric acids is governed by:

• Akiyama Chem Rev 2007
• Terada ChemComm 2008

Reviews to check through for comments on mechanism of reactions and possible applications of Bronsted acids that have not yet been applied to the PS.

• S.J. Connon, Angew. Chem. Int. Ed. 2006, 45, 3909–3912
• T. Akiyama, J. Itoh, K. Fuchibe, Adv. Synth. Catal. 2006, 348, 999 – 1010
• M. S. Taylor, E. N. Jacobsen, Angew. Chem. Int. Ed. 2006, 45, 1520–1543
• Connon, S. J. Org. Biomol. Chem. 2007, 5, 3407–3417
• Terada Synthesis 2010, 1929-1982
• List, Top. Curr. Chem. 2010, 291, 395-456
• Rueping Angewandte 2011, 50, 6706-6720
• S.-L. You, Q. Cai, M. Zeng, Chem. Soc. Rev. 2009, 38, 2190 – 2201
• A. Zamfir, S. Schenker, M. Freund, S. B. Tsogoeva, Org. Biomol. Chem. 2010, 8, 5262 – 5276 (DOI: 10.1039/c0ob00209g)

Bronsted Acids: N-triflyl phosphoramide Yamamoto 2006, N-triflyl phosphoramide [10.1002/anie.200802139 Rueping 2008] , ? Rueping 2010
Diastereoselective polycyclization involving unactivated Ph using SnCl₄ Yamamoto 2006 - suggestion here to use this enantioselectively.

Link from PS page - MNR

Nakamura 2009 - but Aza-Friedel-Crafts Alkylation of Pyrroles
Possible alternative thiophosphoramide: Yamamoto 2008

• Asymmetric Bronsted Acid Catalyzed Nucleophilic Addition to in situ Generated Chiral N-Acyliminium Ions, Rueping, M.; Nachtsheim, B. J. Synlett 2010, 1, 119. (DOI: 10.1055/s-0029-1218539) - KAB: Probably needs to go in the B acid section.

Organocatalysis Section

This section is done.

Mechanism section

Some possibly relevant papers arising from Dixon 2010, on chiral counterion-induced enantioselective N-acyliminium ion reactions:

• Li, G.; Kaplan, M. J.; Wojtas, L.; Antilla, J. C. Org. Lett. 2010, 12, 1960.
• Terada, M.; Machioka, K.; Sorimachi, K. Angew. Chem., Int. Ed. 2009, 48, 2553.
• Rueping, M.; Lin, M.-Y. Chem.sEur. J. 2010, 16, 4169.

Some papers on dual catalysis referenced by Franz 2011:

• Yamamoto, H.; Futatsugi, K. Angew. Chem., Int. Ed. 2005, 44, 1924–1942
• Lv, J.; Li, X.; Zhong, L.; Luo, S.; Cheng, J.-P. Org. Lett. 2010, 12, 1096–1099
• Rueping, M.; Koenigs, R. M.; Atodiresei, I. Chem. Eur. J. 2010, 16, 9350–9365.

The general reviews need to be checked, to ensure we have not missed anything, and as inspiration for thoughts on the reaction mechanism. e.g. Govindra Org Reactions review we've already cited.

Enzymatic Section

Abe, 2015 (10.1016/j.chembiol.2015.06.006) - Already included, however did not cover stereoselectivity of McbB.

Papers that may need to be included under Expanding our Knowledge of the Pictet-Spenglerase Family subsection under Enzymatic Catalysis:

Monoamine Oxidase (MAO-N)'

• Turner, 2013 ACS Catal. (10.1021/cs400724g)

Nonribosomal polypeptide synthetase, SfmC

• Oikawa, 2010 (10.1038/nchembio.365)
• Oikawa, 2012 (10.1016/j.cbpa.2012.02.021)
• Oikawa, 2012(2), Book chapter (10.1016/B978-0-12-394291-3.00026-5)

(R)-Salsolinol synthase in human and rat brains

• Naoi, 1996 (10.1016/0304-3940(96)12807-X)
• Naoi, 2004 (10.1016/S0161-813X(03)00099-8)
• Deng, 2011 (10.2478/s11756-011-0134-y)
• Deng, 2013 (10.1134/S1819712413030045)
• Deng, 2014 (10.3892/ijmm.2013.1604)

Human morphine biosynthesis

• Zenk, 2005 ([http://dx.doi.org/10.1073