Hydroboration–oxidation reaction

Chemical reaction that converts an alkene to an alcohol

Hydroboration–oxidation reaction is a two-step hydration reaction that converts an alkene into an alcohol.[1] The process results in the syn addition of a hydrogen and a hydroxyl group where the double bond had been. Hydroboration–oxidation is an anti-Markovnikov reaction, with the hydroxyl group attaching to the less-substituted carbon. The reaction thus provides a more stereospecific and complementary regiochemical alternative to other hydration reactions such as acid-catalyzed addition and the oxymercuration–reduction process. The reaction was first reported by Herbert C. Brown in the late 1950s[2] and it was recognized in his receiving the Nobel Prize in Chemistry in 1979.

The general form of the reaction is as follows:

Tetrahydrofuran (THF) is the archetypal solvent used for hydroboration.

## Mechanism and scope

[edit]

### Hydroboration step

[edit]

Main article: hydroboration

In the first step, borane (BH3) adds to the double bond, transferring one of the hydrogen atoms to the carbon adjacent to the one that becomes bonded to the boron. This hydroboration is repeated two additional times, successively reacting each B–H bond so that three alkenes add to each BH3. The resulting trialkylborane is treated with hydrogen peroxide in the second step. This process replaces the B-C bonds with HO-C bonds. The boron reagent is converted to boric acid. The reaction was originally described by H.C. Brown in 1957 for the conversion of 1-hexene into 1-hexanol.[3]

Hexanol synthesis

Knowing that the group containing the boron will be replaced by a hydroxyl group, it can be seen that the initial hydroboration step determines the regioselectivity. Hydroboration proceeds in an anti-Markovnikov manner. The reaction sequence is also stereospecific, giving syn addition (on the same face of the alkene): the hydroboration is syn-selective and the oxidation replaces the boron with hydroxyl having the same geometric position. Thus 1-methylcyclopentene reacts with diborane predominantly to give trans-1-hydroxy-2-methylcyclopentane[4]—the newly added H and OH are cis to each other.

Until all hydrogens attached to boron have been transferred away, the boron group BH2 will continue adding to more alkenes. This means that one mole of hydroborane will undergo the reaction with three moles of alkene. Furthermore, it is not necessary for the hydroborane to have more than one hydrogen. For example, reagents of the type R2BH are commonly used, where R can represents the remainder of the molecule. Such modified hydroboration reagents include 9-BBN, catecholborane, and disiamylborane.

### Oxidation step

[edit]

In the second step of the reaction sequence, the nucleophilic hydroperoxide anion attacks the boron atom. Alkyl migration to oxygen gives the alkyl borane with retention of stereochemistry (in reality, the reaction occurs via the trialkyl borate B(OR)3, rather than the monoalkyl borinic ester BH2OR).

Hydroboration–oxidation mechanism

The 'H' atom in the reaction comes from B2H6, the 'O' atom comes from hydrogen peroxide (H2O2) whereas the O attached 'H' atom comes from the solvent (refer mechanism).

## Alkyne hydroboration

[edit]

A hydroboration reaction also takes place on alkynes. Again the mode of action is syn and secondary reaction products are aldehydes from terminal alkynes and ketones from internal alkynes. In order to prevent hydroboration across both the pi-bonds, a bulky borane like disiamyl (di-sec-iso-amyl) borane is used.[5]

Hydroboration–oxidation of terminal alkyne

## Alternative oxidations

[edit]

Use of other oxidants instead of hydrogen peroxide can lead to carbonyl products rather than alcohols from alkenes. N-Methylmorpholine N-oxide with catalytic tetrapropylammonium perruthenate converts the alkylborane into a carbonyl, thus a ketone or aldehyde product depending on what other groups were attached to that carbon in the original alkene.[6] Various dichromates or related chromium(VI) reagents give ketones as well, but give carboxylic acids instead of aldehydes for terminal alkenes.[7]

## Other oxidation substrates

[edit]

Aside from boranes, the oxidation of silanes and disilanes can also yield hydroxy groups. A major difference is that while silyl groups like the phenyldimethylsilyl group are converted to the hydroxy group after acid or other electrophile treatment followed by oxidation by hydrogen peroxide, disilanyl groups are converted after TBAF treatment followed by peroxide oxidation. This allows for selective oxidation of either group.[8]

## References

[edit]

1. ^ Marc G. Loudon (2002). "Addition Reactions of Alkenes". Organic Chemistry (fourth ed.). New York: Oxford University Press. pp. 168–172\. ISBN 0-19-511999-1.
2. ^ Brown, H. C.; Zweifel, G. (1959). "A Sterepspecific Cis Hydration of the Double Bond in Cyclic Derivatives". Journal of the American Chemical Society. 81 (1): 247. Bibcode:1959JAChS..81Q.247B. doi:10.1021/ja01510a059.
3. ^ Brown, H.; Rao, B. C. (1957). "Communications – Selective Conversion of Olefins into Organoboranes Through Competitive Hydroboration, Isomerization and Displacement Reactions". Journal of Organic Chemistry. 22 (9): 1137. doi:10.1021/jo01360a626.
4. ^ Hawthorne, M. F. (1961). "Amine Boranes. VIII. The Hydroboration of Terminal Olefins, Dienes and Terminal Acetylenes with Trimethylamine t-Butylborane". Journal of the American Chemical Society. 83 (11): 2541–2544\. Bibcode:1961JAChS..83.2541H. doi:10.1021/ja01472a027.
5. ^ Brown, H. C.; Gupta, S. K. (1972). "Catecholborane (1,3,2-benzodioxaorole) as a new, general monohydroboration reagent for alkynes. Convenient synthesis of alkeneboronic esters and acids from alkynes via hydroboration". Journal of the American Chemical Society. 94 (12): 4370. Bibcode:1972JAChS..94.4370B. doi:10.1021/ja00767a072.
6. ^ Yates, Matthew H. (1997). "One-pot conversion of olefins to carbonyl compounds by hydroboration / NMO–TPAP oxidation". Tetrahedron Lett. 38 (16): 2813–2816\. doi:10.1016/S0040-4039(97)00476-0.
7. ^ Brown, Herbert C.; Kulkarni, Shekhar V.; Khanna, Vijay V.; Patil, Virendra D.; Racherla, Uday S. (1992). "Organoboranes for Synthesis. 14. Convenient Procedures for the Direct Oxidation of Organoboranes from Terminal Alkenes to Carboxylic Acids". Journal of Organic Chemistry. 57 (23): 6173–6177\. doi:10.1021/jo00049a024.
8. ^ Suginome, Michinori; Matsunaga, Shin-ichiro; Ito, Yoshihiko (September 1995). "Disilanyl Group as a Synthetic Equivalent of the Hydroxyl Group". Synlett. 1995 (9): 941–942\. doi:10.1055/s-1995-5150.

## External links

[edit]

* Organic Chemistry Portal. Hydroboration (including recent literature). https://www.organic-chemistry.org/namedreactions/brown-hydroboration.shtm

* v
* t
* e

Topics in organic reactions

* Addition reaction
* Elimination reaction
* Polymerization
* Reagents
* Rearrangement reaction
* Redox reaction
* Regioselectivity
* Stereoselectivity
* Stereospecificity
* Substitution reaction

* A value
* Alpha effect
* Annulene
* Anomeric effect
* Antiaromaticity
* Aromatic ring current
* Aromaticity
* Baird's rule
* Baker–Nathan effect
* Baldwin's rules
* Bema Hapothle
* Beta-silicon effect
* Bicycloaromaticity
* Bredt's rule
* Bürgi–Dunitz angle
* Catalytic resonance theory
* Charge remote fragmentation
* Charge-transfer complex
* Clar's rule
* Conformational isomerism
* Conjugated system
* Conrotatory and disrotatory
* Curtin–Hammett principle
* Dynamic binding (chemistry)
* Edwards equation
* Effective molarity
* Electromeric effect
* Electron-rich
* Electron-withdrawing group
* Electronic effect
* Electrophile
* Evelyn effect
* Flippin–Lodge angle
* Free-energy relationship
* Grunwald–Winstein equation
* Hammett acidity function
* Hammett equation
* George S. Hammond
* Hammond's postulate
* Homoaromaticity
* Hückel's rule
* Hyperconjugation
* Inductive effect
* Kinetic isotope effect
* LFER solvent coefficients (data page)
* Marcus theory
* Markovnikov's rule
* Möbius aromaticity
* Möbius–Hückel concept
* More O'Ferrall–Jencks plot
* Negative hyperconjugation
* Neighbouring group participation
* 2-Norbornyl cation
* Nucleophile
* Kennedy J. P. Orton
* Passive binding
* Phosphaethynolate
* Polar effect
* Polyfluorene
* Ring strain
* Σ-aromaticity
* Spherical aromaticity
* Spiroaromaticity
* Steric effects
* Superaromaticity
* Swain–Lupton equation
* Taft equation
* Thorpe–Ingold effect
* Vinylogy
* Walsh diagram
* Woodward–Hoffmann rules
* Woodward's rules
* Y-aromaticity
* Yukawa–Tsuno equation
* Zaitsev's rule
* Σ-bishomoaromaticity

List of organic reactions

Carbon-carbon
bond forming
reactions|

* Acetoacetic ester synthesis
* Acyloin condensation
* Aldol condensation
* Aldol reaction
* Alkane metathesis
* Alkyne metathesis
* Alkyne trimerisation
* Alkynylation
* Allan–Robinson reaction
* Arndt–Eistert reaction
* Auwers synthesis
* Aza-Baylis–Hillman reaction
* Barbier reaction
* Barton–Kellogg reaction
* Baylis–Hillman reaction
* Benary reaction
* Bergman cyclization
* Biginelli reaction
* Bingel reaction
* Blaise ketone synthesis
* Blaise reaction
* Blanc chloromethylation
* Bodroux–Chichibabin aldehyde synthesis
* Bouveault aldehyde synthesis
* Bucherer–Bergs reaction
* Buchner ring expansion
* Cadiot–Chodkiewicz coupling
* Carbonyl allylation
* Carbonyl olefin metathesis
* Castro–Stephens coupling
* Chan rearrangement
* Chan–Lam coupling
* Claisen condensation
* Claisen rearrangement
* Claisen-Schmidt condensation
* Combes quinoline synthesis
* Corey–Fuchs reaction
* Corey–House synthesis
* Coupling reaction
* Cross-coupling reaction
* Cross dehydrogenative coupling
* Cross-coupling partner
* Dakin–West reaction
* Darzens reaction
* Diels–Alder reaction
* Doebner reaction
* Wulff–Dötz reaction
* Ene reaction
* Enyne metathesis
* Ethenolysis
* Favorskii reaction
* Ferrier carbocyclization
* Friedel–Crafts reaction
* Fujimoto–Belleau reaction
* Fujiwara–Moritani reaction
* Fukuyama coupling
* Gabriel–Colman rearrangement
* Gattermann reaction
* Glaser coupling
* Grignard reaction
* Grignard reagent
* Hammick reaction
* Heck reaction
* Henry reaction
* Heterogeneous metal catalyzed cross-coupling
* High dilution principle
* Hiyama coupling
* Homologation reaction
* Horner–Wadsworth–Emmons reaction
* Hydrocyanation
* Hydrovinylation
* Hydroxymethylation
* Ivanov reaction
* Johnson–Corey–Chaykovsky reaction
* Julia olefination
* Julia–Kocienski olefination
* Kauffmann olefination
* Knoevenagel condensation
* Knorr pyrrole synthesis
* Kolbe–Schmitt reaction
* Kowalski ester homologation
* Kulinkovich reaction
* Kumada coupling
* Liebeskind–Srogl coupling
* Malonic ester synthesis
* Mannich reaction
* McMurry reaction
* Meerwein arylation
* Methylenation
* Michael reaction
* Minisci reaction
* Mizoroki-Heck vs. Reductive Heck
* Nef isocyanide reaction
* Nef synthesis
* Negishi coupling
* Nierenstein reaction
* Nitro-Mannich reaction
* Nozaki–Hiyama–Kishi reaction
* Olefin conversion technology
* Olefin metathesis
* Palladium–NHC complex
* Passerini reaction
* Peterson olefination
* Pfitzinger reaction
* Piancatelli rearrangement
* Pinacol coupling reaction
* Prins reaction
* Quelet reaction
* Ramberg–Bäcklund reaction
* Rauhut–Currier reaction
* Reformatsky reaction
* Reimer–Tiemann reaction
* Rieche formylation
* Ring-closing metathesis
* Robinson annulation
* Sakurai reaction
* Seyferth–Gilbert homologation
* Shapiro reaction
* Sonogashira coupling
* Stetter reaction
* Stille reaction
* Stollé synthesis
* Stork enamine alkylation
* Suzuki reaction
* Takai olefination
* Thermal rearrangement of aromatic hydrocarbons
* Thorpe reaction
* Ugi reaction
* Ullmann reaction
* Wagner-Jauregg reaction
* Weinreb ketone synthesis
* Wittig reaction
* Wurtz reaction
* Wurtz–Fittig reaction
* Zincke–Suhl reaction

| Homologation reactions|

* Arndt–Eistert reaction
* Hooker reaction
* Kiliani–Fischer synthesis
* Kowalski ester homologation
* Methoxymethylenetriphenylphosphorane
* Seyferth–Gilbert homologation
* Wittig reaction

|

Olefination reactions|

* Bamford–Stevens reaction
* Barton–Kellogg reaction
* Boord olefin synthesis
* Chugaev elimination
* Cope reaction
* Corey–Winter olefin synthesis
* Dehydrohalogenation
* Elimination reaction
* Grieco elimination
* Hofmann elimination
* Horner–Wadsworth–Emmons reaction
* Hydrazone iodination
* Julia olefination
* Julia–Kocienski olefination
* Kauffmann olefination
* McMurry reaction
* Peterson olefination
* Ramberg–Bäcklund reaction
* Shapiro reaction
* Takai olefination
* Wittig reaction

Carbon-heteroatom
bond forming
reactions|

* Azo coupling
* Bartoli indole synthesis
* Boudouard reaction
* Cadogan–Sundberg indole synthesis
* Diazonium compound
* Esterification
* Grignard reagent
* Haloform reaction
* Hegedus indole synthesis
* Hurd–Mori 1,2,3-thiadiazole synthesis
* Kharasch–Sosnovsky reaction
* Knorr pyrrole synthesis
* Leimgruber–Batcho indole synthesis
* Mukaiyama hydration
* Nenitzescu indole synthesis
* Oxymercuration reaction
* Reed reaction
* Schotten–Baumann reaction
* Ullmann condensation
* Williamson ether synthesis
* Yamaguchi esterification

Degradation
reactions|

* Barbier–Wieland degradation
* Bergmann degradation
* Edman degradation
* Emde degradation
* Gallagher–Hollander degradation
* Hofmann rearrangement
* Hooker reaction
* Isosaccharinic acid
* Marker degradation
* Ruff degradation
* Strecker degradation
* Von Braun amide degradation
* Weerman degradation
* Wohl degradation

Organic redox
reactions|

* Acyloin condensation
* Adkins–Peterson reaction
* Akabori amino-acid reaction
* Alcohol oxidation
* Algar–Flynn–Oyamada reaction
* Amide reduction
* Andrussow process
* Angeli–Rimini reaction
* Aromatization
* Autoxidation
* Baeyer–Villiger oxidation
* Barton–McCombie deoxygenation
* Bechamp reduction
* Benkeser reaction
* Bergmann degradation
* Birch reduction
* Bohn–Schmidt reaction
* Bosch reaction
* Bouveault–Blanc reduction
* Boyland–Sims oxidation
* Cannizzaro reaction
* Carbonyl reduction
* Clemmensen reduction
* Collins oxidation
* Corey–Itsuno reduction
* Corey–Kim oxidation
* Corey–Winter olefin synthesis
* Criegee oxidation
* Dakin oxidation
* Davis oxidation
* Deoxygenation
* Dess–Martin oxidation
* DNA oxidation
* Elbs persulfate oxidation
* Emde degradation
* Eschweiler–Clarke reaction
* Étard reaction
* Fischer–Tropsch process
* Fleming–Tamao oxidation
* Fukuyama reduction
* Ganem oxidation
* Glycol cleavage
* Griesbaum coozonolysis
* Grundmann aldehyde synthesis
* Haloform reaction
* Hydrogenation
* Hydrogenolysis
* Hydroxylation
* Jones oxidation
* Kiliani–Fischer synthesis
* Kolbe electrolysis
* Kornblum oxidation
* Kornblum–DeLaMare rearrangement
* Leuckart reaction
* Ley oxidation
* Lindgren oxidation
* Lipid peroxidation
* Lombardo methylenation
* Luche reduction
* Markó–Lam deoxygenation
* McFadyen–Stevens reaction
* Meerwein–Ponndorf–Verley reduction
* Methionine sulfoxide
* Miyaura borylation
* Mozingo reduction
* Noyori asymmetric hydrogenation
* Omega oxidation
* Oppenauer oxidation
* Oxygen rebound mechanism
* Ozonolysis
* Parikh–Doering oxidation
* Pinnick oxidation
* Prévost reaction
* Reduction of nitro compounds
* Reductive amination
* Riley oxidation
* Rosenmund reduction
* Rubottom oxidation
* Sabatier reaction
* Sarett oxidation
* Selenoxide elimination
* Shapiro reaction
* Sharpless asymmetric dihydroxylation
* Epoxidation of allylic alcohols
* Sharpless epoxidation
* Sharpless oxyamination
* Stahl oxidation
* Staudinger reaction
* Stephen aldehyde synthesis
* Swern oxidation
* Transfer hydrogenation
* Wacker process
* Wharton reaction
* Whiting reaction
* Wohl–Aue reaction
* Wolff–Kishner reduction
* Wolffenstein–Böters reaction
* Zinin reaction

Rearrangement
reactions|

* 1,2-rearrangement
* 1,2-Wittig rearrangement
* 2,3-sigmatropic rearrangement
* 2,3-Wittig rearrangement
* Achmatowicz reaction
* Alkyne zipper reaction
* Allen–Millar–Trippett rearrangement
* Allylic rearrangement
* Alpha-ketol rearrangement
* Amadori rearrangement
* Arndt–Eistert reaction
* Aza-Cope rearrangement
* Baker–Venkataraman rearrangement
* Bamberger rearrangement
* Banert cascade
* Beckmann rearrangement
* Benzilic acid rearrangement
* Bergman cyclization
* Bergmann degradation
* Boekelheide reaction
* Brook rearrangement
* Buchner ring expansion
* Carroll rearrangement
* Chan rearrangement
* Claisen rearrangement
* Cope rearrangement
* Corey–Fuchs reaction
* Cornforth rearrangement
* Criegee rearrangement
* Curtius rearrangement
* Demjanov rearrangement
* Di-π-methane rearrangement
* Dimroth rearrangement
* Divinylcyclopropane-cycloheptadiene rearrangement
* Dowd–Beckwith ring-expansion reaction
* Electrocyclic reaction
* Ene reaction
* Enyne metathesis
* Favorskii reaction
* Favorskii rearrangement
* Ferrier carbocyclization
* Ferrier rearrangement
* Fischer–Hepp rearrangement
* Fries rearrangement
* Fritsch–Buttenberg–Wiechell rearrangement
* Gabriel–Colman rearrangement
* Group transfer reaction
* Halogen dance rearrangement
* Hayashi rearrangement
* Hofmann rearrangement
* Hofmann–Martius rearrangement
* Ireland–Claisen rearrangement
* Jacobsen rearrangement
* Kornblum–DeLaMare rearrangement
* Kowalski ester homologation
* Lobry de Bruyn–Van Ekenstein transformation
* Lossen rearrangement
* McFadyen–Stevens reaction
* McLafferty rearrangement
* Meyer–Schuster rearrangement
* Mislow–Evans rearrangement
* Mumm rearrangement
* Myers allene synthesis
* Nazarov cyclization reaction
* Neber rearrangement
* Newman–Kwart rearrangement
* Overman rearrangement
* Oxy-Cope rearrangement
* Pericyclic reaction
* Piancatelli rearrangement
* Pinacol rearrangement
* Pummerer rearrangement
* Ramberg–Bäcklund reaction
* Ring expansion and contraction
* Ring-closing metathesis
* Rupe reaction
* Schmidt reaction
* Semipinacol rearrangement
* Seyferth–Gilbert homologation
* Sigmatropic reaction
* Skattebøl rearrangement
* Smiles rearrangement
* Sommelet–Hauser rearrangement
* Stevens rearrangement
* Stieglitz rearrangement
* Thermal rearrangement of aromatic hydrocarbons
* Tiffeneau–Demjanov rearrangement
* Vinylcyclopropane rearrangement
* Wagner–Meerwein rearrangement
* Wallach rearrangement
* Weerman degradation
* Westphalen–Lettré rearrangement
* Willgerodt rearrangement
* Wolff rearrangement

Ring forming
reactions|

* 1,3-Dipolar cycloaddition
* Annulation
* Azide-alkyne Huisgen cycloaddition
* Baeyer–Emmerling indole synthesis
* Bartoli indole synthesis
* Bergman cyclization
* Biginelli reaction
* Bischler–Möhlau indole synthesis
* Bischler–Napieralski reaction
* Blum–Ittah aziridine synthesis
* Bobbitt reaction
* Bohlmann–Rahtz pyridine synthesis
* Borsche–Drechsel cyclization
* Bucherer carbazole synthesis
* Bucherer–Bergs reaction
* Cadogan–Sundberg indole synthesis
* Camps quinoline synthesis
* Chichibabin pyridine synthesis
* Cook–Heilbron thiazole synthesis
* Cycloaddition
* Darzens reaction
* Davis–Beirut reaction
* De Kimpe aziridine synthesis
* Debus–Radziszewski imidazole synthesis
* Dieckmann condensation
* Diels–Alder reaction
* Feist–Benary synthesis
* Ferrario–Ackermann reaction
* Fiesselmann thiophene synthesis
* Fischer indole synthesis
* Fischer oxazole synthesis
* Friedländer synthesis
* Gewald reaction
* Graham reaction
* Hantzsch pyridine synthesis
* Hegedus indole synthesis
* Hemetsberger indole synthesis
* Hofmann–Löffler reaction
* Hurd–Mori 1,2,3-thiadiazole synthesis
* Iodolactonization
* Isay reaction
* Jacobsen epoxidation
* Johnson–Corey–Chaykovsky reaction
* Knorr pyrrole synthesis
* Knorr quinoline synthesis
* Kröhnke pyridine synthesis
* Kulinkovich reaction
* Larock indole synthesis
* Madelung synthesis
* Nazarov cyclization reaction
* Nenitzescu indole synthesis
* Niementowski quinazoline synthesis
* Niementowski quinoline synthesis
* Paal–Knorr synthesis
* Paternò–Büchi reaction
* Pechmann condensation
* Petrenko-Kritschenko piperidone synthesis
* Pictet–Spengler reaction
* Pomeranz–Fritsch reaction
* Prilezhaev reaction
* Pschorr cyclization
* Reissert indole synthesis
* Ring-closing metathesis
* Robinson annulation
* Sharpless epoxidation
* Simmons–Smith reaction
* Skraup reaction
* Urech hydantoin synthesis
* Van Leusen reaction
* Wenker synthesis

| Cycloaddition|

* 1,3-Dipolar cycloaddition
* 4+4 Photocycloaddition
* (4+3) cycloaddition
* 6+4 Cycloaddition
* Alkyne trimerisation
* Aza-Diels–Alder reaction
* Azide-alkyne Huisgen cycloaddition
* Bradsher cycloaddition
* Cheletropic reaction
* Conia-ene reaction
* Cyclopropanation
* Diazoalkane 1,3-dipolar cycloaddition
* Diels–Alder reaction
* Enone–alkene cycloadditions
* Hexadehydro Diels–Alder reaction
* Intramolecular Diels–Alder cycloaddition
* Inverse electron-demand Diels–Alder reaction
* Ketene cycloaddition
* McCormack reaction
* Metal-centered cycloaddition reactions
* Nitrone-olefin (3+2) cycloaddition
* Oxo-Diels–Alder reaction
* Ozonolysis
* Pauson–Khand reaction
* Povarov reaction
* Prato reaction
* Retro-Diels–Alder reaction
* Staudinger synthesis
* Trimethylenemethane cycloaddition
* Vinylcyclopropane (5+2) cycloaddition
* Wagner-Jauregg reaction

|

Heterocycle forming reactions|

* Algar–Flynn–Oyamada reaction
* Allan–Robinson reaction
* Auwers synthesis
* Bamberger triazine synthesis
* Banert cascade
* Barton–Zard reaction
* Bernthsen acridine synthesis
* Bischler–Napieralski reaction
* Bobbitt reaction
* Boger pyridine synthesis
* Borsche–Drechsel cyclization
* Bucherer carbazole synthesis
* Bucherer–Bergs reaction
* Chichibabin pyridine synthesis
* Cook–Heilbron thiazole synthesis
* Diazoalkane 1,3-dipolar cycloaddition
* Einhorn–Brunner reaction
* Erlenmeyer–Plöchl azlactone and amino-acid synthesis
* Feist–Benary synthesis
* Fischer oxazole synthesis
* Gabriel–Colman rearrangement
* Gewald reaction
* Hantzsch ester
* Hantzsch pyridine synthesis
* Herz reaction
* Knorr pyrrole synthesis
* Kröhnke pyridine synthesis
* Lectka enantioselective beta-lactam synthesis
* Lehmstedt–Tanasescu reaction
* Niementowski quinazoline synthesis
* Nitrone-olefin (3+2) cycloaddition
* Paal–Knorr synthesis
* Pellizzari reaction
* Pictet–Spengler reaction
* Pomeranz–Fritsch reaction
* Prilezhaev reaction
* Robinson–Gabriel synthesis
* Stollé synthesis
* Urech hydantoin synthesis
* Wenker synthesis
* Wohl–Aue reaction

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template