The Vespiary

The Hive => Chemistry Discourse => Topic started by: Lego on June 14, 2004, 12:01:00 AM

Title: Reduction methods in organic synthesis
Post by: Lego on June 14, 2004, 12:01:00 AM: Overview over synthetic reduction methods

1) Reduction of C-C-Bonds
2) Reduction of C-O Bonds
3) Reduction of C-N Bonds
4) Reductive functional group conversion
5) Reduction of other functional groups, e.g. nitro groups, sulphur containing groups, ...
6) Various

1) Reduction of C-C-Bonds
reduction of C=C bond in nitrostyrenes
Zinc borohydride:
Post 510437 (https://www.thevespiary.org/talk/index.php?topic=11374.msg51043700#msg51043700)
(Rhodium: "Nitroalkene Reduction with Zinc Borohydride", Novel Discourse)
MeOH/NaBH₄:
Post 510662 (https://www.thevespiary.org/talk/index.php?topic=11679.msg51066200#msg51066200)
(Rhodium: "Varma & Kabalka: Nitroalkene -BH4-> Nitroalkane", Novel Discourse)
Borohydride Exchange Resin:
Post 510662 (https://www.thevespiary.org/talk/index.php?topic=11679.msg51066200#msg51066200)
(Rhodium: "Varma & Kabalka: Nitroalkene -BH4-> Nitroalkane", Novel Discourse)
HCOOH/triethylamine:
Post 444306 (https://www.thevespiary.org/talk/index.php?topic=11875.msg44430600#msg44430600)
(Lego: "Formic acid and triethylamine", Novel Discourse)
Hantzsch ester/silical gel:
Post 500814 (https://www.thevespiary.org/talk/index.php?topic=11875.msg50081400#msg50081400)
(azole: "reduction with Hantzsch ester/SiO2 (full article)", Novel Discourse)
NaBH₄/PTC:
Post 426052 (https://www.thevespiary.org/talk/index.php?topic=11742.msg42605200#msg42605200)
(Barium: "Novel high-yielding C=C reduction of nitrostyrenes", Novel Discourse)
RhCl₃/H₂/PTC:
Post 398684 (https://www.thevespiary.org/talk/index.php?topic=11359.msg39868400#msg39868400)
(Barium: "C=C bond hydrogenation of beta-nitrostyrene", Novel Discourse)
benzaldehyde/o-phenylenediamine:
Post 352950 (https://www.thevespiary.org/talk/index.php?topic=11875.msg35295000#msg35295000)
(Barium: "Get that double bond without borohydride", Novel Discourse),
Post 352950 (https://www.thevespiary.org/talk/index.php?topic=11875.msg35295000#msg35295000)
(Barium: "Get that double bond without borohydride", Novel Discourse)

general C=C reduction methods
PdCl₂/H₂:
Post 470158 (missing)
(azole: "reductions with NaAlH4 in hydrocarbon media", Russian HyperLab)

2) Reduction of C-O Bonds
Reduction of carboxylic acids & esters to aldehydes
Sodium bis-(2-methoxy-ethoxy) aluminium hydride/saccharine:
Post 405255 (https://www.thevespiary.org/talk/index.php?topic=11499.msg40525500#msg40525500)
(GC_MS: "acid > aldehyde", Novel Discourse)
PdCl₂/H₂/N-ethylmorpholine/2-chloro-4,6-dimethoxy[1,3,5]triazine:
Post 430441 (https://www.thevespiary.org/talk/index.php?topic=11644.msg43044100#msg43044100)
(Lego: "Reduction of carboxylic acids to aldehydes", Novel Discourse)
NaH₂PO₂/Pd(OAc)₂/tricyclohexylphospine/pivalic anhydride:
Post 304273 (https://www.thevespiary.org/talk/index.php?topic=12364.msg30427300#msg30427300)
(karel: "Aldehydes from carboxylic acids", Serious Chemistry)

Reduction of carboxylic acids & esters to alcohols
Zinc borohydride:
Post 485626 (https://www.thevespiary.org/talk/index.php?topic=11374.msg48562600#msg48562600)
(Lego: "Zn(BH4)2/Pyridine also reduces COOH, Pt. 1", Novel Discourse)
NaAlH₄:
Post 470158 (missing)
(azole: "reductions with NaAlH4 in hydrocarbon media", Russian HyperLab)
LiBH₄:
Post 413088 (https://www.thevespiary.org/talk/index.php?topic=11865.msg41308800#msg41308800)
(Rhodium: "Reduction of esters to alcohols w/ in situ LiBH4", Novel Discourse)

Reduction of carboxylic acids & esters to hydrocarbons
LiAlH₄/AlCl:₃
Post 476162 (https://www.thevespiary.org/talk/index.php?topic=11906.msg47616200#msg47616200)
(Rhodium: "A One-Step Ester to Hydrocarbon Reduction", Novel Discourse)
Triethylsilane/B(C₆F₅)₃:
Post 194986 (https://www.thevespiary.org/talk/index.php?topic=12508.msg19498600#msg19498600)
(Rhodium: "First published direct reduction of COOH to CH3", Serious Chemistry)

Reduction of carboxylic acid chlorides to aldehydes
Na₄/pyridine:
Post 509148 (https://www.thevespiary.org/talk/index.php?topic=6522.msg50914800#msg50914800)
(Rhodium: "NaBH4:Pyridine: Acid Chlorides to Aldehydes", Chemistry Discourse)
Na₄/PCC:
Post 491806 (missing)
(Vitus_Verdegast: "benzoylchloride -> benzaldehyde w NaBH4/PCC", Chemistry Discourse)
HCOOH:
Post 464426 (missing)
(Lilienthal: "acid chlorides to aldehydes with formic acid", Tryptamine Chemistry)

Reduction of carboxylic acid chlorides to alcohols

Reduction of carboxylic acid chlorides to hydrocarbons

Reduction of aldehydes & acetals to alcohols
Zinc borohydride:
Post 435043 (https://www.thevespiary.org/talk/index.php?topic=11374.msg43504300#msg43504300)
(Rhodium: "Zn(BH4)2/Pyridine reduces carbonyl compounds", Novel Discourse)

Reduction of aldehydes & acetals to hydrocarbons
CTH/NH₄HCOO:
Post 507520 (https://www.thevespiary.org/talk/index.php?topic=11757.msg50752000#msg50752000)
(Rhodium: "CTH reduction of various functional groups", Novel Discourse)

Reduction of alcohols to hydrocarbons
HI/RP:
Post 511694 (https://www.thevespiary.org/talk/index.php?topic=8190.msg51169400#msg51169400)
(Rhodium: "HI/RP reduction of aminoalcohols", Stimulants)
Me₃SiCl-NaI-CH₃CN:
Post 507401 (https://www.thevespiary.org/talk/index.php?topic=11705.msg50740100#msg50740100)
(Rhodium: "Me3SiCl-NaI-MeCN: Benzylic Alcohol Deoxygenation", Novel Discourse)

3) Reduction of C-N Bonds
Reduction of imines to amines
PMHS:
Post 505083 (https://www.thevespiary.org/talk/index.php?topic=6790.msg50508300#msg50508300)
(Lego: "Asymetric reduction of imines with PMHS", Chemistry Discourse)

Reduction of enamines to amines

Reduction of nitriles to amines
Bu₄BH₄:
Post 507503 (missing)
(Rhodium: "Nitriles and Amides to Amines with n-Bu4BH4", Novel Discourse)
CoCl₂/NaBH₄:
Post 507524 (https://www.thevespiary.org/talk/index.php?topic=11798.msg50752400#msg50752400)
(Rhodium: "Reduction of Nitrile/Nitro/Amide to Primary Amines", Novel Discourse)

Reduction of amides to amines
Bu₄BH₄:
Post 507503 (missing)
(Rhodium: "Nitriles and Amides to Amines with n-Bu4BH4", Novel Discourse)
CoCl₂/NaBH₄:
Post 507524 (https://www.thevespiary.org/talk/index.php?topic=11798.msg50752400#msg50752400)
(Rhodium: "Reduction of Nitrile/Nitro/Amide to Primary Amines", Novel Discourse)

Thioamides to amines
Post 470674 (https://www.thevespiary.org/talk/index.php?topic=12405.msg47067400#msg47067400)
(Lego: "Reduction of secondary thioamide with Zn/HCl", Serious Chemistry)

4) Reductive functional group conversion
Reductive amination - ketone/aldehyde to amine
Zinc borohydride:
Post 481426 (https://www.thevespiary.org/talk/index.php?topic=11374.msg48142600#msg48142600)
(dioulasso: "N-methylation of amines with Zn(BH4)2", Novel Discourse)
Titanium(IV)isopropoxide/NaBH₄:
Post 364157 (https://www.thevespiary.org/talk/index.php?topic=12009.msg36415700#msg36415700)
(Rhodium: "Titanium(IV)isopropoxide reductive amination", Novel Discourse),
Post 485344 (missing)
(Lego: "Reductive amination with Ti(iPrO)4/NaBH4", Novel Discourse)
Zn/iPrOH/mol sieves:
Post 413690 (https://www.thevespiary.org/talk/index.php?topic=11394.msg41369000#msg41369000)
(Lego: "Red. amination with Zn/iPrOH and mol. sieves", Novel Discourse)
NaBH(OAc)₃:
Post 503100 (https://www.thevespiary.org/talk/index.php?topic=12124.msg50310000#msg50310000)
(Rhodium: "NaBH(OAc)3 in Reductive Amination", Novel Discourse)
Cl₃SiH/DMF:
Post 458268 (https://www.thevespiary.org/talk/index.php?topic=11789.msg45826800#msg45826800)
(Rhodium: "Trichlorosilane-DMF for Reductive Amination", Novel Discourse)

Alcohol to amine (no real reduction)

Nitroalkenes to ketone/aldehyde
Chromium chloride:
Post 512099 (https://www.thevespiary.org/talk/index.php?topic=11910.msg51209900#msg51209900)
(Rhodium: "Varma&Kabalka: Cr(II) Nitrostyrene Reduction", Novel Discourse)

5) Reduction of other functional groups, e.g. nitro groups, sulphur containing groups, ...
Nitro to amine
Zn/ammonium formate:
Post 351892 (https://www.thevespiary.org/talk/index.php?topic=6879.msg35189200#msg35189200)
(foxy2: "Reduction of nitro groups w. Zinc/Ammonium formate", Chemistry Discourse)
Zinc borohydride:
Post 435007 (missing)
(Lego: "Zn(BH4)2/Pyridine reduces nitro compounds", Novel Discourse)
Mg/Hydrazinium Monoformate:
Post 512087 (https://www.thevespiary.org/talk/index.php?topic=11670.msg51208700#msg51208700)
(Rhodium: "Nitro -> Amine with Mg/Hydrazinium Monoformate", Novel Discourse)
Titan(II):
Post 474130 (missing)
(Lego: "Selective reduction of nitro compounds with Ti(II)", Novel Discourse)
NaBH₄/NiCl₂: 505481
CHT/NH₄HCOO:
Post 507520 (https://www.thevespiary.org/talk/index.php?topic=11757.msg50752000#msg50752000)
(Rhodium: "CTH reduction of various functional groups", Novel Discourse)
Sn complex:
Post 508071 (https://www.thevespiary.org/talk/index.php?topic=6539.msg50807100#msg50807100)
(Rhodium: "Reduction of Nitro/Azide groups with Sn complex", Chemistry Discourse)
CoCl₂/NaBH₄:
Post 507524 (https://www.thevespiary.org/talk/index.php?topic=11798.msg50752400#msg50752400)
(Rhodium: "Reduction of Nitrile/Nitro/Amide to Primary Amines", Novel Discourse)

Azides to amines
Zn/NH₄Cl:
Post 399263 (https://www.thevespiary.org/talk/index.php?topic=11319.msg39926300#msg39926300)
(endo1: "The reduction of azides to amines w zinc/amoniumCl", Novel Discourse)

Nitroalkenes to aldoximes/ketoximes
CoCl₂:
Post 512099 (https://www.thevespiary.org/talk/index.php?topic=11910.msg51209900#msg51209900)
(Rhodium: "Varma&Kabalka: Cr(II) Nitrostyrene Reduction", Novel Discourse)
SnCl₂:
Post 507809 (https://www.thevespiary.org/talk/index.php?topic=9579.msg50780900#msg50780900)
(Rhodium: "Varma & Kabalka: SnCl2 Nitroalkene -> Oxime", Methods Discourse)
CTH/NaH₂PO₂:
Post 509830 (https://www.thevespiary.org/talk/index.php?topic=11910.msg50983000#msg50983000)
(Rhodium: "Hypophosphite CTH: Nitroalkenes to Oximes", Novel Discourse)

Nitroalkenes to aminoalkanes
BH₃·THF:
Post 511296 (https://www.thevespiary.org/talk/index.php?topic=9013.msg51129600#msg51129600)
(Rhodium: "Nitroalkenes to Amines w/ BH3·THF made in situ", Methods Discourse)
LiAlH₄:
Post 506993 (https://www.thevespiary.org/talk/index.php?topic=11427.msg50699300#msg50699300)
(Rhodium: "Mescaline, Amphetamine etc. by LAH reduction", Novel Discourse)

Oximes to amines
Mg/NH₄HCOO:
Post 498659 (missing)
(demorol: "Reduction of Oximes using Mg/Ammonium Formate", Novel Discourse)
Zn/NH₃:
Post 413177 (https://www.thevespiary.org/talk/index.php?topic=11788.msg41317700#msg41317700)
(Lego: "Reduction of ketoximes with Zn/NH3", Novel Discourse)

Sulphonic acids to thiols/thiophenols

6) Various
Reviews
Nitroalkenes:
Post 510333 (https://www.thevespiary.org/talk/index.php?topic=11910.msg51033300#msg51033300)
(Rhodium: "Nitroalkene Synthesis & Reduction Review", Novel Discourse),
Post 509994 (https://www.thevespiary.org/talk/index.php?topic=11910.msg50999400#msg50999400)
(Rhodium: "Varma & Kabalka: Nitroalkene Reduction Review", Novel Discourse)
Hydrides:
Post 502900 (https://www.thevespiary.org/talk/index.php?topic=11393.msg50290000#msg50290000)
(Rhodium: "Comprehensive Hydride Reduction Review", Novel Discourse)
Clemmens reduction:
Post 508503 (https://www.thevespiary.org/talk/index.php?topic=12101.msg50850300#msg50850300)
(Rhodium: "Organic Reactions: The Clemmensen Reduction", Novel Discourse)
Wolff-Kishner Reduction:
Post 508584 (https://www.thevespiary.org/talk/index.php?topic=12101.msg50858400#msg50858400)
(Rhodium: "Organic Reactions: The Wolff-Kishner Reduction", Novel Discourse)

Removal of protecing groups
Mg/hydrazinium monoformate:
Post 499259 (https://www.thevespiary.org/talk/index.php?topic=11316.msg49925900#msg49925900)
(Rhodium: "Great, Demorol!", Novel Discourse)