Organic Chemistry 1 Reaction Collection

Radical Halogenation

SM: alkane and X-X

Mechanism: initiation, propagation, and termination

Product: alkyl halide

RDS: 1st step of propagation

Sn2

Nu: 1. good Nu/SB 2. good Nu/WB 3. poor Nu/SB

E-LG: methyl, 1º unhindered, 1º branched(WB)

Solvent: polar aprotic

Mechanism: concerted, backside attack

Product: Substitution at LG- causes inversion

RDS: exothermic, early ts(look like sm)

Sn1

Nu: 1. poor Nu/WB 2. good Nu/WB

E-LG: 2º, 3º(good Nu)

Solvent: polar protic

Mechanism: 2-step, C+ intermediate

Product: most substituted product, can have stereoisomers

RDS: endothermic, late ts(look like products)

E1

Nu: 1. poor Nu/WB 2. good Nu/WB

E-LG: 2º, 3º(good Nu)

Mechanism: 2-step, C+ intermediate

Product: most substituted alkene, can have stereoisomers

RDS: endothermic, late ts(look like products)

E2

Nu: 1. good Nu/SB 2. poor Nu/SB*

E-LG: 1º branched, 2º, 3.º, 1º unhindered(poor Nu)

Solvent: polar aprotic

Mechanism: concerted attack

Product: most substituted alkene(less sub if bulky base)

RDS: exothermic, early ts(look like sm)

Williamson Ether Synthesis

SM: alcohol + 1º unhindered or methyl alkyl halide

Reagent(s): non-nucleophilic STRONG base, NaH or NaNH2

Mechanism: SB deprotonates OH to form alkoxide, attacks alkyl halide for Sn2

Product: ether!

Symmetric Acid Synthesis

SM: 2 eq. identical alcohols

Reagent(s): H2SO4

Mechanism: protonate OH using H2SO4, make H2O leave, form C+( 2º, 3º), other OH attacks, deprotoate

Product: symmetric ether!

Asymmetric Acid Synthesis

SM: 2 differently substituted alcohols- more sub. alcohol is E-LG

Reagent(s): H2SO4

Mechanism: protonate less sub alcohol to make good LG, H2O leaves, C+ forms, Nu alcohol attacks, deprotonate

Product: asymmetric ether!

Symmetrical Ether Cleavage

SM: symmetrical ether, 1º=Sn2/ 2º,3º= Sn1

Reagent(s): strong nucleophilic acid- H-X

Mechanism: protonate O, kick off LG and split into alcohol & alkane w/C+. use X to attack C+ then protonate OH, H20 leaves and X attacks new C+

Product: identical alkyl halides!

Asymmetrical Ether Cleavage

SM: ether, more substituted side forms C+

Reagent(s): strong nucleophilic acid- H-X

Mechanism: protonate O, kick off LG, and form alcohol and more sub C+, use X to attack C+ and protonate OH, H2O leaves and X attacks new C+

Product: 2 diff substituted alkyl halides

Fischer Esterification

SM: carboxylic acid & alcohol

Reagent(s): H2SO4

Mechanism: protonoate carbonyl O, SnAc from OH to carbonyl C & break C=O pi bond, grab H from 1st OH with COOH's OH to make H2O, SnAc(2) regenerates carbonyl and kicks off LG, deprotonate OH on C=O using HO3SO

Product: ester!

Masked Hydroxide Synthesis (intro to SnAc)

SM: 1º branched, 2º, 3º alkyl halide

Reagent(s): acetate to mask OH, then NaOH

Mechanism: acetate O attacks alkyl halide, X leaves, [Na]OH attacks carbonyl and breaks pi bond, pi bond reforms and LG leaves alkane, OH protonates O on alkane

Product: alcohol and acetate

Alcohol Activation- strong acids

SM: 1º alcohol

Reagent(s): H-X

Mechanism: protonate OH, then Sn2

Product: H20=good LG

Alcohol Activation- inversion

SM: 1º, 2º alchols

Reagent(s): PBr3 or PCl3

Mechanism: Sn2 with OH as Nu, PX3 as E-LG, PX3 attaches to OH, X is Nu, attacks α C & OH+ PX2 are LG

Product: INVERSION and X replaces OH

Alcohol Activation- inversion

SM: 1º, 2º alcohols

Reagent(s): SOCl2 and pyridine (mild base)

Mechanism: SnAc from Oh to SOCl2, S=O pi bond breaks, SnAc(2) kicks off Cl and reforms S=O, pyridine deprotonates OH, Sn2 with Cl as Nu & O-SOCl as LG

Product: INVERSION and Cl replaces OH

ALcohol Activation- retention

SM: 1º, 2º, 3º alcohols

Reagent(s): [mesyl chloride(ClMs)/tosyl chloride(ClTs)/ trifilic anhydride(TfOTf)] + pyridine

Mechanism: SnAc from Oh to sulfonyl chloride, S=O pi bond breaks, SnAc(2) kicks off Cl and reforms S=O, pyridine deprotonates OH, Sn2 with Cl as Nu & O-SOCl as LG

Product: OH replaced by OMs/OTs/ OTf

Alcohol Activation dehydration

SM: 1º alcohol=E2 or 2º,3º alcohols= E1

Reagent(s): H2SO4, heat

Mechanism: elimination rxn, carbocation rearrangement if E1

Product: most stable alkene/ E2= Zaitzev unless X or sulfonate ester LG, then Hofmann

Epoxide Opening- basic conditions

SM: epoxide

Reagent(s): LiALH4, RMgBr, RLI, RC≡CNa & diethyl ether

Mechanism: lone pair attacks less sub side(INVERSION), sends e- back to O, acidic workup

Product: less subbed OH, less subbed Nu addition

Epoxide Opening: acidic conditions

SM: epoxide

Reagent(s): strong acid like H-X or H2SO4 & HOCH3

Mechanism: protonate O, HOCH3 attacks more subbed side, and sends e- back to O, HOCH3 deprotonates HOCH3

Product: less subbed OH, more subbed Nu addition

Epoxide Synthesis

SM: halohydrin(alcohol 2 C's away from a halogen)

Reagent(s): NaH or NaNH2

Mechanism: intermolecular williamson ether synthesis, NaH deprotonates OH, O attacks C and X gets kicked off

Product: epoxide!

Organometallics

SM: alkyl halide

Reagent(s): Mg or 2eq Li

Mechanism: Mg adds between C and X, Li replaces X

Product: VERY SB, can form new C-C bonds at carbonyls & epoxides- can reduce carbonyls to alcohols

Oxidation

SM: 1.º, 2º alcohol

Reagent(s): PCC( CrO3, HCl, pyridine) or Jones(CrO3, H2SO4, H2O) HM: Tollens(Ag2O, NH4OH, H2O)

Product: 1º OH to aldehyde(pcc)/COOH(jones)

2º OH to ketone( pcc/jones)

aldehyde to COOH (jones/tollens)

Reduction

SM: ketone/aldehyde/COOH/ester

Reagent(s): LiALH4/NaBH4/ organometallic

Product: ester/COOH to 1º OH (LiALH4)

aldehyde to 1º OH/ketone to 2º OH(LiAlH4/NaBH4)

ketone to 3º OH/aldehyde to 2º OH (organometallic)

ester to 3º OH (2 eq organometallic)

Aldol Addition

SM: 2 carbonyls (ketone/aldehyde)

Reagent(s): NaOH, H2O

Mechanism: deprotonate β C, form pi bond to α C, break C=O pi bond, reform C=O & α=β pi bond attacks α C on ketone- breaks its C=O pi bond, protonate O-

Product: β-hydroxy carbonyl

Aldol Condensation

SM:β-hydroxy carbonyl

Reagent(s): NaOH, heat

Mechanism: deprotonate β C, form pi bond to α C, break C=O pi bond, reform C=O pi bond, move α=β pi bond over to OH C, OH leaves

Product: α,β- unsaturated carbonyl

Hydrogenation of alkenes

SM: alkene

Reagent(s): H2, Pd/C or Ptº

Mechanism: H-H bonds to Ptº, H attacks C & pi bond sends e- to Ptº, other C attacks last H and sends its e- back to Ptº

Product: SYN addition of H's on either side of alkene

Hydrohalogenation of alkenes

SM: alkene

Reagent(s): H-X

Mechanism: pi bond grabs H, C+ forms on other side, X attacks C+ and attaches

Product: MARKOVNIKOV addition- H on less sub C & X on more sub C

Hydration of alkenes

SM: alkene

Reagent(s): H2SO4 + H20

Mechanism: pi bond grabs H from H2SO4 & C+ forms on other side, OH2 attacks C+, OH2 deprotonates OH2

Product: MARKOVNIKOV addition- H on less sub side & OH on more sub side

Alkene Isomerization

SM: alkene

Reagent(s): H2SO4

Mechanism: pi bond grabs H & C+ forms on other side(possible C+ rearrangement), E1!= OSO3H grabs H to form most substituted alkene(zaitzev)

Product: major: more subbed alkene / minor: less subbed alkene

Halogenation of Alkenes

SM: alkene

Reagent(s): X-X

Mechanism: pi bond grabs X & X lp attacks other side of alkene- forming 3-membered ring, X attacks C & sends e- back to X in ring using Sn2

Product: ANTI addition of X on either side

Halohydrin Synthesis

SM: alkene

Reagent(s): X-X, HOH or ROH

Mechanism: pi bond attacks X and X lp attacks other side of alkene- forming 3-membered ring, OH2 attacks more sub C and sends e- back to X in ring

Product: ANTI addition of X and OH, X at less sub C & OH at more sub C

Oxymercuration-Reduction

SM: alkene

Reagent(s): 1. Hg(OAc)2, HOH or HOR

2. NaBH4, NaOH

Mechanism: pi bond attacks Hg & Hg lp attacks back- forming 3-membered ring, OH2 attacks more sub side & sends e- back to Hg, step 2 fixes everything

Product: ANTI/MARKOVNIKOV addition- forms more sub OH/OR group

Hydroboration-Oxidation

SM: alkene

Reagent(s): 1. BH3

2. H2O2, NaOH

Mechanism: pi bond attacks B & H attacks more sub- forming 3-membered ring, step 2 fixes everything

Product: SYN/ANTI-MARKOVNIKOV addition- forms less sub OH

Epoxidation

SM: alkene

Reagent(s): peracetic acid/ trifluoroperacetic acid, mCPBA

Mechanism: pi bond attacks OH's O, O-O bond sends e- to from O=C pi bond, current O=C pi bond grabs OH's H, and OH bond attacks pi bond to form epoxide

Product: concerted SYN addition- epoxide!

Syn-dihydroxylation

SM: alkene

Reagent(s): OsO4 w/ H2S/Znº OR amine oxide

Mechanism: pi bond attacks one of Os=O, pi bond sends e- to Os and other Os=O pi bond attacks back to alkene- forming 5-membered ring, H2S/Znº or amine oxide create OH on either side

Product: SYN addition- OH on both C of alkene

Ozonolysis- reductive

SM: alkene

Reagent(s): 1. O3

2. S(CH3)2

Mechanism: pi bond attacks O≡O, triple bond sends e- to central O, O-O attacks back to alkene- forming 5-membered ring(molozonide), 1 O forms C=O & sigma bond sends e- to form other C=O & last O-O bond is broken, C=O with other O pi bond is broken & other O attacks other C=O & that C=O pi bond attacks first C=O's C- formoning an ozonide, S(CH3)2 finishes reduction

Product: ketones and/or aldehydes

Ozonolysis- oxidative

SM: alkene

Reagent(s): 1. O3

2. H2O2 + H2O

Mechanism: pi bond attacks O≡O, triple bond sends e- to central O, O-O attacks back to alkene- forming 5-membered ring(molozonide), 1 O forms C=O & sigma bond sends e- to form other C=O & last O-O bond is broken, C=O with other O pi bond is broken & other O attacks other C=O & that C=O pi bond attacks first C=O's C- formoning an ozonide, H2O2 + H2O finishes oxidation

Product: ketones and/or carboxylic acids

Internal Alkyne Synthesis

SM: internal vicinal halogens on alkane

Reagent(s): 2 eq NaNH2

Product: internal alkyne

Terminal Alkyne Synthesis

SM: terminal vicinal halogens on alkane

Reagent(s): excess NaNH2, H3O+

Mechanism: form acetylide(terminal alkyne with lp and - charge) & use H3O+ wokrup to protonate and neutralize charge

Product: terminal alkyne

Sn2 with Alkyl Halides & Alkynes

SM: terminal alkyne

Reagent(s): SB like NaH, NaNH2, organolithium, or grignard

Mechanism: SB turns alkyne into acetylide, then can react with alkyl halide to perform Sn2

Product: internal alkyne

Hydrogenation of alkynes- Full Reduction

SM: internal alkyne

Reagent(s): H2, Pd/C or Ptº

Mechanism: 2x hydrogenation rxn

Product: 2x SYN addition of H's

Hydrogenation of alkynes- Partial Reduction (cis)

SM: internal alkyne

Reagent(s): H2 + Lindlar's catalyst- Pd/CaCO3, Pb(OAc)2, quinoline

Product: SYN addition of H- cis alkene

Hydrogenation of alkynes- Partial Reduction (trans)

SM: internal alkyne

Reagent(s): H2 + Naº, NH3

Mechanism: C≡C grabs radical from Na, one of pi bonds on C≡C gives 1 e- to each C, C with lp grabs H from NH3, C with radical grabs radical from Na- now has lp, this C grabs H from NH3

Product: ANTI addition of H- trans alkene

Hydrohalogenation of alkynes

SM: alkyne

Reagent(s): 1 eq H-X, followed by excess H-X

Mechanism: alkyne pi bond grabs H from HX, can stop at alkene, or can continue and repeat to form alkane product

Product: MARKOVNIKOV addition- geminal halogens on more subbed side

Halogenation of alkynes

SM: alkyne

Reagent(s): 1 eq X-X, followed by excess X-X

Mechanism: alkyne pi bond grabs X & l X lp attacks bacl- fomring 3-membered ring, other X attacks one side of alkene, sending e- back to X in ring, can stop here to form alkene or can continue and repeat to form alkane product

Product: ANTI addition- forms vicinal, geminal halogens

Hydration of alkynes- using catalytic Hg2+

SM: alkyne

Reagent(s): HgSO4, H2SO4, H2O

Mechanism: alkyne pi bond attacks Hg & Hg lp attacks back- forming 3-membered ring. OH2 attacks more sub side and sends e- back to Hg, OH forms pi bond to C and alkene grabs H from HOSO3H, Hg lp sends e- back to reform alkene, pi bodn to OH breaks, OH reforms pi bond to C and alkene grabs another H from HOSO3H, OH2 deprotonates OH

Product: MARKOVNIKOV carbonyl- ketone

Hydration of alkynes- using hydroboration-oxidation

SM: alkyne

Reagent(s): 1. R2BH

2. H2O2, NaOH

Mechanism: alkyne pi bond attacks B, H attacks back- concerted SYN addition, step 2 reagents make basic conditions- replace B with O to form enolate, O forms pi bond to C, alkene grabs H from H2O,

Product: ANTI-MARKOVNIKOV carbonyl-aldehyde