JOC Year in Review: 1989 Baran Group Meeting Justine …

SelectedIsolations

NH

Me

OH

Me

MeMe

NH

Me

OH

Me

MeMe

tubingensen A (4743) nominine (2530)

NO

O

N

Me

O

O

Me

HO2C

H

H

H

HH

H

H

HOMe

gelsamydine (3199)

Me

isocyanoneopupkeanane (2095)

MeMe

CNMe

MeO

O

O

MeOOMe

NH

R

R=H, limalongineR=Cl, chlolimalongine (3491)

O

MeO Me

O

HO

Me

R

R=α-Me, R1=H, crotoxide A

R=CH2, R1=α,β-OH, crotoxide B (1654)

R1

O O

CO2MeO

Me H

H

(±)-sarracenin

NH

N H

O

H

(±)-meloscine (α-H)(±)-epimeloscine (β-H)

O

H

Me

OH

OH

OAc

Me

Me

HOO

forskonlin

N

N NMe

MeOMe

(±)-alchorneine

N

NN

O

Me

O

amphimedine

Me

CO2H

Me

MeMe

H

HMe

retigeranic acid

SynthesesDiscussed

SomeSynthesesNotCovered• Danishefsky,13-oxygenatedprostanoids.6016-6018.• Nicholaou,geomertric isomersoflipoxin-A4andlipoxin-B4.5527-5535.•Meyers,unnatural(+)-aspidopermine.4673-4676.• Paquette,trixikingolide.3334-3337.• Boger,K-13.2498-2502.

Publication Record Paquette, L.A. 14Padwa, A. 9Brown, H.C. 9Fraserreid, B. 8Faulkner, D.J. 8Rapoport, H. 7 Olah, G.A. 7Marchand, A.P. 7Clardy, J. 7Barrett, A.G.M. 7Schreiber, S.L. 6Lenoble, W. J. 6

Top 5 Most Cited1. "Investigation of the Synthesis of Ortho-Substituted Tetraphenyl- porphyrins." Lindsey, J.S.; Wagner, R.W. 54(4), 828-836.

2. "Atom Transfer Cyclization Reactions of Alpha-Iodo Esters, Ketones, and Malonates - Examples of Selective 5-exo, 6-endo, 6-exo, and 7- endo Ring Closures." Curran, D.P.; Chang, C.T. 54(13), 3140-3157.

3. "Host Guest Complexation .48. Octol Building-Blocks for Cavitands and Carcerands." Tunstad, L.M.; Tucker, J.A.; Dalcanale, E.; et al. 54(6), 1305-1312.

4. "Absolute Electronegativity and Hardness - Applications to Organic- Chemistry." Pearson, R.G. 54(6), 1423-1430.

5. "Substituted 1,4-Dihydropyrimidines .3. Synthesis of Selectively Functionalized 2-Hetero-1,4-Dihydropyrimidines." Atwal, K.S.; Rovnyak, G.C.; OReilly, B.C.; et al. 54(25), 5898-5907.

Noble Prize- Chemistry Altman, S. and Cech, T.R. "for their discovery of catalytic properties of RNA"Wolf Prize- Chemistry Battersby, A.R. and Arigoni, D. "for their fundamental contributions to the elucidation of the mechanism of enzymic reactions and of the biosynthesis of natural products, in particular the pigments of life"Priestley Medal Pimentel, G.C.

General StatsVolume: 54Issues: 1-26Pages 1-6140Total Articles: 1,372

Notable Events- Jan. 20: George H.W. Bush inaugurated - Mar. 24: Exxon Valdez tanker rupture in AK- June 4: Tiananmen Square Massacre- Nov. 11: Berlin Wall opens to the West

See also: K. Foo 2011 GM, "JACS Year in Review: 1989"

Justine deGruyterBaran Group Meeting

05/23/2015JOC Year in Review: 1989

AnodicOxidationofStudiesofp-Methoxyanilides.AGeneralMethodforPreparationofAcylated Quinone Imine Ketals.Swenton,J.S.;Bonke,B.R.;Chen,C.-P.;Chou,C.-T.51-58.

O

O

N2

Rh2(OAc)4

O

CHO

O

O

N2Rh2(OAc)4

O H

O

O

CHO

H+

OH

CHO

S O

N2

S S

O

H+[Rh]

O

CH2CH2COCHN2[Rh]

O

O

O

O

O

HO

HO

H+

Intramolecular Cyclopropanation ReactionofFuranyl Diazo Ketones.Padwa,A.;Wisnieff,T.J.;Walsh,E.J.299-308.

N

R

EWG

NMe

OON

NMePhOC

O

O

H

HH

CH2CHEWG

NMe

O

O

N

NMe

O

O

EWG

PhOC

N

NMe

O

O

HN

O

O

H

H

H

H

HHH

H

H

PhOC

AShort,Oxetane-BasedSynthesisof(±)-Sarracenin.Hoye,T.R.andRichardson,W.S.688-693.

Electron-DeficientIsoxazoles:1,3-DipolarCycloadditions ofEthyl4-nitro-3-phenylisoxazole-5-carboxylatewithDiazoalkanes.Nesi,R.;Giomi,D.;Papaleo,S.;Bracci,S.706-708.

NO

E

NO2Ph

N

O

N

N

Ph NO2

ER

R

N

O

R R

NO2

E

N

O

N

Ph NO2

E

N

H

N

O

Ph

N

N

E

N

O

Ph

N

N

E

N

N

N

O

Ph

N

N

E

N

N

R2C=N2

R=H, Me

-N2R=H

-HNO2

xs

H2C=N2

H2C=N2

-N2

H Me

Ohυ

OMeH

Me HOH

CR2

CO2Me

OHC

Me HOH

CR2

CO2MeOHC

OHMe

HOOH

Me

H HO MeH

CR2

CO2Me

O O

CO2MeO

Me H

H

OHC E

" "

O3

H+

1. remove " "

2. O3

"-OH" 1. activate "-OH"

2.OHC E

" "

(±)-sarracenin

Tandem1,3-DipolarCycloadditions ofPyridinium orIsoquinoliniumMethylides withOlefinic Dipolarophiles LeadingtoCycl[3.2.2]azines.EnamineRouteasaNewGenerationMethodofAzomethine Ylides.Kanemasa,S.;Takenaka,S.;Watanabe,H.;Tsuge,O.420-424.

HN R 1

O

R2

OMe

R 3

N

O

R 1

R2

R 3

MeO OMe

-2 e-

LiClO4, MeOH,

NaHCO3 or

2,6-lutidine

HN

O

R

OMe

HN

O

R

MeO OMe

R=H, OMe ?

An anomaly.



MediatedElectrochemicalSynthesisofAromaticAldehydes,Ketones,andQuinonesUsingCeric Methanesulfonate.Kreh,R.P.;Spotnitz,R.M.;Lundquist,J.T.1526-1531.

Me

Me

Me

Me Me

CHO

Me

Me

O

O

PhMe PhCHO

PhEt PhCOMe

1,1-Bis(methylthio)-2-(phenylsulfonyl)ethene:AUsefulKeteneAnionEquivalent.Yamamoto,M.;Takemori,T.;Iwasa,S.;Kohmoto,S.;Yamada,K.1757-1760.

• O

PhO2S

"doubly umpolunged enolate equivalent"

SMe

SMe

PhO2S

SMe

SMeE

PhO2S

E+= MeI, BnBr, BzCl, BnCHO, acrolein, MVK, TMSCl, CH3CHCH2O, PhNCO

SMe

SMe

PhO2S

Me

O

Me

OH

CO2Et

SO2PhO

SO2Ph

O

Me

in EtOH:in tBuOH:

56%0%

28%96%

SMe

SMe

PhO2S

R

HO pTsOH

O O

SO2Ph

R O OR

Al(Hg)

R= MeR= Ph

86%98%

33%68%

1. NaBH4

2. pTsOH in ROH

nBuLi

E+

Me3SiN3 2 F3CSO3H NH2N2+OSO2CF3

- Me3SiOSO2CF3

NH2N2+OSO2CF3

-

R NH2

H

- F3CSO3-

RNH2

R

+ + substratebenzenetolueneo-xylenemesitylenePhClPhBr

yield (%)959693959373

o: m: p

54: 9: 37

45: 7: 4852: 6: 42

Trimethylsilyl Azide/Triflic Acid,aHighlyEfficientElectrophilic Aminating Reagent.Olah,G.A.;Ernst,T.D.1203-1204.

Me3SiOOSiMe3

R OSiMe3

H

ROH

R CF3SO3H

- H+

then CF3SO3H

substratebenzenetoluenemesityleneo-xylene

naphthalene

PhCl

yield (%)77889463

92

76

o: m: p

63: 10: 27

(2,3-)48: (2,6-)22: (3,4-)30(α-) 67: -- : (β-) 3363: -- : 37

DABCO 30% H2O2 DABCO•H2O2 (Me3SiO)2+THF

0°C

TMSClCH2Cl2

0°C

Oxyfunctionalization ofHydrocarbons.14.Electrophilic HydroxylationofAromaticswithBis(trimethylsilyl)Peroxide/Triflic Acid.Olah,G.A.;Ernst,T.D.1204-1206.

NO

Ph

H

Ph

H2C C CHSO2Ph

NH

O

SO2Ph

Ph

H+NH

SO2Ph

N

PhPh

O

PhO2S

rt

SynthesisoftheBenzazepin-4-oneRingSystemviaDipolarCycloaddition ofN-Phenylnitrones withActivatedAllenes.Padwa,A.;Kline,D.N.;Norman,B.H.810-817.

TotalSynthesisof(±)-Meloscine and(±)-Epimeloscine.Overman,L.E.;Robertson,G.M.;Robichaud,A.J.1236-1238.

O

O

O

O

Me

13 steps NMeO2C

H

OBnO

NC OTMS

NHBoc

N

O

O

H

OBnO

BocHN

HNH

OBn

HO

BocHN

N

X

O

HBocHN

NH

OBn

MeO2C

BocHN

NH

N H

O

H

X

(±)-meloscine (α-H)(±)-epimeloscine (β-H)

1. THF, −70°C 3 M HCl quench

2. LiOH, MeOH

1. Ph3P=CH2, rt2. KOH, EtOH 130°C

paraformaldehyde

CSA, PhH, reflux

X=H

X=N2

hν xs KOH

EtOH/H2O0°C to 150°C

Et2O/MeOH



OH

NH2NH2

X

NHRNHR NHR

NR

NHR

NHR

Nu

OH

NHZNHZ

OSO2Me

NHZNHZNHZ

NHZ

CN

NHZ

NHZ

Cl

NHZ

NZ

NHZ

NHZ

OR

R=OCCH3

R=H

General Scheme.

KCN, 18-c-6

NaH/DMF

1. KOtBu/THF2. CH3CO2H, reflux

1. NaH/DMF2. 5% HCl

5% HCl CH3CO2H

MeCN

K2CO3

MeOH:H2O

Selected Examples.

NHTs

NHTs

OTs

NHTs

NTs

NHTs

NHTs

Me

N

Ts

O

CO2Et

TsHN

NHTs

NHTs

CO2H

NaOMe

MeOH

MeMgBr, THFCH2(CO2Et)2

NaOEt, EtOH

6 N HCl

AConvenientSynthesisofVicinalDiamines.Jones,D.A.;Arinivasan,A.;Kasina,S.;Fritzberg,A.R.;Wilkening,D.W.1940-1943.

TheFIrst ExampleofaCatalyticWittig-TypeReaction.Tri-n-butylarsine-CatalyzedOlefination inthePresenceofTriphenyl Phosphite.Shi,L.;Wang,W.;Wang,Y.;Huang,Y.-Z.2026-2028.

SynthesisofOxidizedSpiroketals via2-FurylKetone Oxidation-Rearrangment.Perron,F.;Albizati,K.F.2044-2047.

RCHO + BrCH2X + (PhO3)P

n-Bu3As (cat.), K2CO3 (s)

THF-MeCN, rtR

X + (OPh3)P

R=p-ClPhPhH2-furyl2-thiophenyl2-pyridylPhCH=CH

X= CO2CH3, C(O)Ph

Yield (%)878680756861

n-Bu3As

n-Bu3As+CH2XBr-

n-Bu3As+C-HX

n-Bu3AsO

BrCH2X

K2CO3

RCHO

RCH=CHX

(PhO)3P

(PhO)3PO

OR

OR Li O

R OH

OO

O

O

R

HO

O

OTBS

O

OTBS

O

O

O O

Me

OH

O

O

O

Me

OHOH

nBuLi

THF, −78°C

O

O

−78°C

2.0 equivNBS

aq. THF0°C to rt

+

Mechanistic Pathways for N-dealkylations of Amines by Cytrochrome P-450.

R N

O

R1

R2

R= PhCH2CH2,

Ph, p-O2NC6H4,

C6F5, H

R1= CH3, CD3

R2= CH3, CD3,

H, CHO, CH2OCH3,

CH2OH

R N

O

R1(R2)1

H

Substrate Scope.

ElectrochemicalModelforCytochrome P-450.N-Demethylation ofTertiaryAmidesbyAnodicOxidation.Hall,L.R.;Iwamoto,R.T.;Hanzlik,R.P.2446-2451.

Electroorganic Chemistry.116.ElectrochemicalTransformationofAldoximes toNitriles UsingHalogenIonsasMediators.IntermediaryFormationofNitrile Oxides.Shono,T.;Matsumura,Y.;Tsubata,K.;Kamade,T.;Kishi,K.2249-2251.General Scheme.

N

R

OHelectricity

electrolyteMeOH

RCN

Mechanism.

Me

Me

Me

N OH

Me

Me

Me

N O

Me

Me

Me

CN

MeN

OH

5

-2e-, NaI

styrene

MeOHN

O

Me(H2C)5

Ph

N

OH -2e-, NaI

styrene

MeOHN

O

Ph

Ph

Ph

Selected Examples.



AFormalSynthesisofForskolin:AnElectrocyclization Approach.Venkataranman,H.;Cha,J.K.2505-2506.

Cyclohexadienone AnnulationsofArylCarbene ComplexesofChromium:NewStrategiesfortheSynthesisofIndole Alkaloids.Bauta,W.E.;Wulff,W.D.;Pavkovic,S.F.;Zaluzec,E.J.3249-3252.

X

R1

(OC)5Cr

OMe

X

OMe

Rs

RLR2

R1

R3R 2

R3

X

R2

R3

OR1

OMe

Rs

RL

NMe

OMOM

OMe

Cr(CO)5

NH

O Ph

benzene, 50°C

NMe

O

HN

PhO

OMe

MOMO

N

N

R1

Me

R 3

R 2

H

R4

Me

vindoline: R1= OMe, R2= OAc

R3= OH, R4= CO2Me

RLC CRs

R1≠ H

?

RLC CRs

R1≠ H

?

InterruptedPolymerizationofAcrylates:SequentialMichael-Michael-DieckmannCyclizations forEasy,One-pot,2+2+2ConstructionofPolyfunctionalizedCyclohexanones.Posner,G.H.;Shulman-Roskes,E.M.3514-3515.

SynthesisofTwoUseful,Enantiomerically PureDerivativesof(S)-4-Hydroxy-2-cyclohexenone.Audia,J.E.;Boisvert,L.;Patten,A.D.;Villalobos,A.;Danishefsky,S.J.3738-3740.

OO

OHHO

HO

MeMe

O

HO

OO

MeMe

O

OO

MeMe

O

OO

MeMe

O

OTBS

O

OH

O

OPMB

OR'

R

OR'H

NaIO4MsCl, TEA

CH2Cl2

H2, Pd(OH)2/C

DBU, TBSClPhH, heat

DBU, PhH or K2CO3, aq. THF

PMBOC(NH)CCl3

DCM

BF3•OEt

Me2CuLi

TMSCl

OTBS

OEt

HgI2

RO

O

R1

R

2

1. LDA

2. 2

3. H+

CO2R

OR

O

RO

O

O

R1

R2

R R1 R2 % Yield

Et

Et

Et

Me

H

H

H

H

H

CH3

Ph

SPh

49

70

66

72

Et

Me

Et

R R1 R2 % Yield

NMe

58

64

45

Functionalization ofOlefinsbyAlkoximidoylnitrenes.Subbaraj,A.;Rao,O.S.;Lwowski,W.3945-3952.

EtOCNSO2CH3

N

ArOCNSO2CH3

N

MeOCNCN

N

EtOCNCN

N

R

+ NG

N

R

G

heat

NHGRCH

R

2

R1CH

R

2

R1

R

2

R1

N

R

H

CH

R

2

R1

H2O

O

H

Me

OH

OH

OAc

Me

Me

HOO

Me

OH

Me Me

O

Me

OCH2OBn

Me Me

MeMe

CO2EtOH

Me Me

MeMe

CO2Et

O

Me Me

MeMe

R 3

R4

O

Me

Me

OMe

O

Me

MeMe

HMe

OH

Me

OH

O

Me

Me

OMe

Me

OH

O

O

O

Me

MeMe

HMe

O

O

4 steps W-2 Raney Ni

EtOH, rt

1. PCC, CH2Cl22. NaBH4, EtOH

1. LAH, Et2O, 0°C

2. tBuOOH, VO(acac)2

PhH

PCC

CH2Cl2

PCC

CH2Cl2

Na, anthraceneTHF

4 steps

forskonlin

R4= R5= O

R= H, R5= OH



Functionalization ofPhenylRingsbyImidoylnitrenes.Dabbagh,H.A.;Lwowski,W.3952-3957.

Synthesesof(±)-Alchorneine and(±)-Isoalchorneine.Buchi,G.;Rodriguez,A.D.;Yakyshijin,K.4494-4496.

O O

H

O O

M

O O

R R

OBuLi

(+MXn)

R+ Amberlyst-15O

OH

pentricin

O O

RBu

O1. BuLi

2. BuIBu

O O

RLi

O OtBu

O

R

O

OMe Me

OH

2. Amberlyst-15 aq. THF

3. H+

1.

ApplicationsofMetalated Cyclopropenone Ketals inaGeneralSynthesisofCyclopropenones.AnEfficientSynthesisoftheAntibioticPenitricin.Isaka,M.;Matsuzawa,S.;Yamago,S.;Ejiri,S.;Miyachi,Y.;Nakamura,E.4727-4729.

Stereocontrolled ConstructionofHydroazylenones bySequentialAnionicOxy-CopeRearrangement-SN'-Allylic EtherDisplacement.Paquette,L.A.;Shi,Y.-J.5205-5207.

O

OR

R1

R4

R2

R 3

R

R1 O[Ru]

R2

R 3R4 O

O

O

R

R1 OH

R2

R 3O

R

R1 OH

R2

R 3R4 OH

R1

O

R

O

R4

R2

R 3

Ru(II) -Ru(II)

R=CH2

R1-R4=H

-Ru(II)

-Ru(II)

2R1-H-Ru(II), -•R4

R1-H

R= (CH2)n

R1-R4= H, alkyl, alkenyl

O

O

R

H

H

R

OR

H

H

R

[Ru]

O

HO

R

O

O RR

Ruthenium(II)-CatalyzedReactionsof1,4-Epiperoxides.Suzuki,M.;Ohtake,H.;Kameya,Y.;Hamanaka,N.;Noyori,R.5292-5302.

EtOCNCN

N

N

NCN

OEt

HN

OEt

NCN

EtOCNSO2CF3

N HN

OEt

NSO2CF3

R

R

R

R

R

R

NHG

NHG

NHG

R'OCNSO2CF3

N

R R R

R

R'OCNSO2CF3

NR RR

NHG NHG

NHG

RR

NH2N

MeS

O

CH2

Na N

N

Me

Me Br

Me

BrBzO

Me

Me

N

CN

Me

OBz

Me

Me

N

Me

OBz

NHOCH3HN

NH2OMe•HCl

PdCl2(CH3CN)2

CH2Cl2, 40°C

Pd(PPh3)4 (cat.)

Et3N, MeCN, 50°C

N

N

HN

OMe

Me

Me

N

N NMe

MeOMe

(±)-alchorneine

O

MeO

H

H

Me

Me

H

H

Me

Me

MeO

H

OH

O

H

Me

Me

HOMe

O

H

A B

+

MeMe

OMeH

O

Me

MeH

H

H

H

H O MeMe

OMe

H

H+ H+

KH, 18-c-6

THF, Δ

O

HH

HMe

Me

OMeH

A

via:

H

O

OMeR

O

OMeR

O

H

H

R



AnExpeditiousRoutetotheNorthernPartofRetigeranic AcidAfrom(R)-Carvone.Llera,J.M.;Fraser-Reid,B.5544-5548.

AnApproachtoAmphimedine andRelatedMarineAlkaloidsUtilizinganIntramolecular Kondrat'eva PyridineSynthesis.Subramanyam,C.;Noguchi,M.;Weinreb,S.M.5580-5585.

NHOCH3

Br

CHO

Br Br

Br

NAcNAc

NAc

(n=1) NH2OCH3-HClBH3-py.

(n=3) Ph3P=CHCO2CH3;Mg, MeOH, DIBAL;NH2OMe-HCl, BH3-py.

BrMgCH2CH=CH2,BH3-THF; H2O2, NaOH;

oxallyl chloride, NH2OMe-HCl;BH3-py.

CH3Li; tBuLi; RCOCl

n

DisplacementsattheNitrogenofLithioalkoxylamides byOrganometallic Reagents.Beak,P.;Selling,G.W.5574-5580.

N

OMe

OR

O

MeO

NH2

1. pTsOH, PhMe,

90°C

2. NaCNBH3, MeOH,

AcOH

N

OMe

NH

MeO2CN

OMe

NH

MeSe O

Me2AlSeMe

PhMe

N

OMe

NH

O

N CO2Me

CNCH2CO2Me

Et3N, Cu2O, THF

N

OMe

N

O

N

HO

1. Ca(BH4)2

THF/MeOH

2. Ac2O, HCO2H

THF, rt

R

R=HR=CHO

N

N

N

OMe

OH

CHO

o-DCB, DBN

150°C

N

N

N

OMe

OH

CHO N

NN

O

Me

O

amphimedine

MnO2, CHCl3rt

StudiesontheSynthesisofIndolo[2,3-a]quinolizidineSystem.Rubiralta,M.;Diez,A.;Bosch,J.5591-5597.

Me

O

Me

O

CO2Me Me

O

CO2Me

O

CO2MeBr

Me

O

CO2MeMe

Br

+

major

O

CO2Me

Me

BrMe

Me

MeO

N

CO2MeMe

Me

MeO

N

Me

Me CO2Me

3:1

+

Me

Me

MeO2C Me

O N

Me

Me

Me

O NRO

Me

Me

Me

MOMO OH

Me

Me

Me

MOMO I

1. LDA/THF

2. HMPA/

NCCO2Me

H2

Rh(Al2O3)

Br2

MeOH/NaOAc

or Br2, CCl4

HN

EtOH

LiBHEt3

THF

1. ClMOM

2. LiBHEt3

I2, PPh3

imidazole

R=H, CH2OCH3

N

OMeMeO2C

N

OMeR1. Ca(BH4) THF, rt

2. CrO3/py. CH2Cl2, rt

MeNC, MeOH,

AcOH, 60°C N

OMe

OR

O

MeO

1. NaNO2, Ac2O, AcOH, 0°C

2. Na2CO3, CCl4, heat3. NaOMe, MeOH, 0°C

R=CH2OH, CHO

N

SO2Ph

CHO

OO

Me

Me

H2NN

SO2Ph

N

O

O

Me

Me N

SO2Ph

HN

O

O

EtHH

N

SO2Ph

N

O

O

EtHH

HO

HN

N

X

EtH

H

X=OCH2CH2O

X=O

PhH

Dean-Stark

pTsOH, PhH

Dean-Stark

BrCH2CH2OH

EtOH, Na2CO3

Et2O

tBuOK, 0°C

4N HClMeOH



Electroreductive Intramolecular CouplingofKetones withOlefins.Shono,T.;Kashimura,S.;Mori,Y.;Hayashi,T.;Soejima,T.;Yamaguchi,Y.6001-6004.

Enantioselective ConstructionofaQuaternaryAsymmetricCarbonCenter:AVersatileSynthesisofα-Alkylα-AminoAcids.Ihara,M.;Takahashi,M.;Niitsuma,H.;Taniguchi,N.;Yasui,K.;Fukumoto,K.5413-5415.

Ph

Me

O

O OH

OMeR

Ph

MeO

O OH

ORMe

major

Ph

MeO

O OH

O

Ph

MeO

O OH

O

Me R>2equiv LDARX

>2equiv LDAMeI

+

Ph

MeO

O

MeEtCO2Me

O2N-C6H4CO2

MeEtCO2Me

Ph

MeO

O

NH2

MeEt

EtO2C NHCOCH2CO2Et

MeEt

(a) (COCl)2; (b) CH2N2; (c) AgOCOPh, MeOH; (d) HPLC; (e) LAH; (f) p-NO2PhCOCl, py., DMAP; (g) (PhO)2PON3, TEA, PhCH2OH; (h) Pd/C, cyclohexene; (i) KOH, 18-c-6; (j) HCl-EtOH; (k) EtO2CCH2COCl, DMAP.

a,b,c,d g,h,d

e,f i,j,k

OTMSOTMS O

Cl

Cl

O

NC

NCDDQ chargetransfercomplex

C-O bond formationTMS-shift

O

O Cl

Cl

OTMS

CN

NC

O

OTMS

NC Cl

Cl

O

OOTMS

Cl

Cl

OH

NC

NC

C-C bond formationTMS-shift

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone(DDQ)OxidationofSilyl Enol EtherstoEnones viaDDQ-SubstrateAdducts.Bhattacharya,A.;DiMichele,L.M.;Dolling,U.-H.;Grabowski,E.J.J.;Grenda,V.J.6118-6120.

VinylOrganoboranes.12.Synthesisof(Z)-1-halo-1-alkenesviahydroboration of1-halo-1-alkynesFollowedbyProtonolysis.Brown,H.C.;Blue,C.D.;Nelson,D.J.;Bhat,N.G.6064-6067.

VinylOrganoboranes.13.AConveniet Stereospecific Synthesisof(Z)-1-halo-1-alkenesfrom1-alkynesvia(E)-1-alkenylboranederivativeswithhalogens.Brown,H.C.;Subrahmanyam,C;Hamaoka,T.;Ravindran,N.;Bowman,D.H.;Misumi,S.;Unni,M.K.;Somayaji,V.;Bhat,N.G.6068-6075.

VinylOrganoboranes.14.AStereospecific Synthesisof(E)-1-halo-alkenesfrom1-alkynes.Brown,H.C.;Hamaoka,T.;Ravindran,N.;Subrahmanyam,C.;Somayaji,V.;Bhat,N.G.6075-6079.

VinylOrganoboranes.15.Mercuration of2-alkenyl-1,3,2-benzodioxaborolesandBoronic Acids.AConvenientStereospecific ProcedurefortheConversionofAlkynesinto(E)-1-halo-1-alkenesviaMercuricSalts.Brown,H.C.;Larock,R.C.;Gupta,S.K.;Rajagopalan,S.;Bhat,N.G.6079-6084.

Notcovered(butworthmentioning):

R R 1

O

R 2R 2

OH

R

R1

C5H11

O

C5H11

OHMe

Me

O

Me

Me Me

HO Me

Me Me

OMe

Me Me

O

O

Me

Me

OH

Me Me

O

Me

Me

OHMeO

+ e

Selected Examples.

+ e, Bu4NBF4

DMF

80%

+ e, Bu4NBF4

DMF

80%

1. +e, 2.5F/mol

TMSCl, Et3N

2. H+

CHO1. +e, 2.5F/mol

TMSCl, Et3N

2. H+



JOC Year in Review: 1989 Baran Group Meeting Justine …

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