JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

Ig Nobels 1993

Chemistry: James Campbell and Gaines Campbell of Lookout Mountain, Tennessee, dedicated deliverers of fragrance, for inventing scent strips, the odious method by which perfume is applied to magazine pages.

Mathematics: Robert Faid of Greenville, South Carolina, farsighted and faithful seer of statistics, for calculating the exact odds (710,609,175,188,282,000 to 1) that Mikhail Gorbachev is the Antichrist.

Statistics:Volume 581540 papers7957 pages

Publication record:Wipf, P. (9)Paquette, L. A. (9)Padwa, A (8)Olah, G. A. (8)Marshall J. A. (8)

Top Movies:Jurassic ParkMrs. DoubtfireSchindler's ListCool Runnings

Top Songs:I Will Always Love You by Whitney HoustonWhoomp! (There It Is) by Tag TeamCan't Help Falling In Love by UB40

Notable Events of 1993Cost of a gallon of gas ~$1.16Buckingham Palace opens doors to publicPentium microprocessor introduced by IntelWorld Wide Web was born at CERNX-Files debutsMichael Jordan retires for the first time15 June 1993 - Formula One world champion James Hunt dies (45)Shane Warne bowls "Ball of the Century" to Mike Gatting in the first Test at Old TraffordEU Farmers protest the reduction in agricultural subsidies due to Maastricht Treaty

Top 5 Most Cited Papers:

Design, Synthesis, and Control of Conducting Polymer Architectures–Structurally Homogenous Poly(3–Alkylthiophenes)McCullough R. D., Lowe R. D., Jayaraman M., Anderson D. L. J. Org. Chem. 1993, 58, 904–912757 citations

An Improved Procedure for the Preparation of the Dess–Martin PeriodinaneIreland R. E., Liu L. B., J. Org. Chem. 1993, 58, 2899641 citations

New Nitric Oxide–Releasing Zwitterions derived from PolyaminesHrabie J. A., Klose J. R., Wink D. A., Keefer L. K., J. Org. Chem. 1993, 58, 1472–1476476 citations

A Convenient Reduction of Amino–Acids and their DerivativesMcKennon M. J., Meyers A. I., Drauz K., Schwarm M., J. Org. Chem. 1993, 58, 3568–3571407 citations

Analysis of 2 C–13 NMR Correlations for Determining the Stereochemistry of 1,3–Diol AcetonidesRychnovsky S. D., Rogers B., Yang G., J. Org. Chem. 1993, 58, 3511–3515358 citations

JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

Me

MeMe Me

NH

CNHN

NH

1. Hg(NO3)22. NaBH4

39%

Me

MeHN

NHMe

HCl, Δ59%

Me

MeHN

NMe

HO

1. O2, Pt, EtOAc2. H2, Pt, 0 °C

Me

MeHN

HN

NaOH, MeOH,reflux, 48 h

97%

Me

MeHN

HNOHLiAlH4,

THF96%

33%

Me

MeHN

MeHNHCl, MeOH87–94%

Alloaristoteline

Serratoline

Aristotelone

Heathcock; JOC, 1993, 58, 564–568

TMSO

1. C6H6, reflux2. NaBH4, CeCl3

60% (2 steps)

OHH

OTMSOH

OHH

OTMS

KH, 18–Cr–6,THF, reflux

80%

OH

O

Devaux; JOC, 1993, 58, 2349–2350

O

O

First synthesis of tricyclic core of Vinigrol

oxy–Cope

O

MeMe

H

O

O

O

chromatography separation of diastereoisomers

Me Me

Me

LiAlH4

MeMe

H

OH

R-(+)-isomer

1. MnO22.

LDA, CdCl2

MeMe

MeMe

H Me

O

OMeOH,

BF3•Et2O, rt

83% Me

O

O

MeMe

OMe

HMe

Me

OMeH

MeO

O

Me

Me Me

OMeH

toluene,µw, 2.5 h97%

Me

Me Me

98%

Me

O

OMe

OMeMe

H

OHMeOH

86%

NH MeLi,

THF55%

racemic

O

O

Me Me

Me

Cl

C6H6, Et3N

(63% 2 steps)

MeO2C

(+)-Longifolene

Fallis; JOC, 1993, 58, 2186–2195

CO2HI

KBrO3,H2SO4

93%I

OO

OOH

Ac2O, 0.5% TsOH,80 °C, 2 h

91%I

O

OAcOAc

OAc

In the absence of TsOH, difficult to obtain reproducible results for acetylation

Ireland; JOC, 1993, 58, 2899

DMP

O

OMe

Me

use oxone instead

JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

NH

HOMe

NH

CHO MeClMg

THFquant. TFA, (CH2OH)2,

150–155 °C

26%NH

MeMe

Me

N

NH

N

Me

MeMe

H

H

NH

NH

H

Me

MeMe

H

H

Yuehchukene

Sheu; JOC, 1993, 58, 5784–5787

N Cl

NO

N

Me

NH

Me

N Cl

NO

N

Me

N

Me

N Cl

NEt

NMe

O

NN Cl

EtN

N

NHMeO

N

NEt N

N

OMe

N

NEt NN

OMe

A

B

LiHMDS/THF, –10 °C, 2h 17% 76%

A B

KOtBu/THF, rt, 5 min 54% 22%

Proudfoot; JOC, 1993, 58, 6996–7000

conditions

name rxn

Conditions

1. nBuLi2. DMF3. 0.1 N HCl

HO

R

TMSMe

9–BBN

1.

2. 2–aminoethanol50%

R = H; 80%R = Me; 81%

HOTMS

Me

R

MeR

H2SO4R = H; 93%R = Me; 86%

Me

R

Me

RRMe

RMe

MeR

H

HR = H; 50%R = Me; 13%

benzene, reflux

Wang; JOC, 1993, 58, 1651–1652

MeO

Me

O

OH MeO

O

O

OMe

OMe

50%, 94% ee

1. NaHMDs2. 1, THF

Davis; JOC, 1993, 58, 1751–1753

MeO

O

O

OMe

OMe

OH

MeO

OOMe

OMeHO

Me Me

ClCl

SO2

ON 1

asymmetric hydroxylation

JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

PdLn

N

NI

Me

H

H

CO2Me

5% Pd(OAc)2,K2CO3, DMF,nBu4NCl, 80 °C

N

N

HCO2Me

Me

H

H

84%N

N

CO2Me

HH

Me

expected product not formed

N

NH

HMe

MeO O

PdLL

H N

NH

H

MeO OH

H

PdLnMe

N

N

HCO2Me

Me

H

H

Rawal; JOC, 1993, 58, 5583–5584

"unexpected Heck"

NH

CO2Me

N

Ph

thermodynamic product

Pd/C, H2,MeOH

NH

CO2Me

N

OH

OH

67% (2 steps)

N

N

O

H

O

Strychnine

10% HClO4/THFrt, 5 h

51 % (2 steps)NH

CO2Me

BnN

CHO

Me3SI, tBuLi, THF,

–20 to 45 °C

NH

CO2Me

BnN

O reflux

NH

NBn2

NH

NHBn

CO2Me

CHO

BF3•Et2O,toluene,

110 °C, 18 h

NH

CO2Me

BnN

Kuehne; JOC, 1993, 58, 7482–7489,Kuehne; JOC, 1993, 58, 7490–7497

OMe

MeO

OMe

OMe

R

OH

R = Ar, Alkyl Het. Ar

R

N3(PhO)2PON3, DBU,toluene, 0 °C to rt

R

OPO(OPh)2

N

HN

N380–90%, ~95% ee

O

OH

99.6% ee

O

N3

O

(PhO)2PON3, DBU

(PhO)2PON3, PPh3(Mitsunobu cond.)

EtO2CN NCO2Et

91% yield(97.5% ee)

1%

81% yield(82% ee)

6–8%

Grabowksi; JOC, 1993, 58, 5886–5888

Practical Alternative to Mitsunobu Conditions for activated alcohols to azides

silica–gel filtration

2 x FCC,1 distillation

Name Rxn

JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

OHTHPOBnN

O NBn

OTHP

Weinreb; JOC, 1993, 58, 4945-4951

320 °C,DCB

BnN

O

OTHP

BnNBnNBnN

O

THPO

H

H H

44%

TsNBnN

OHH

H H

TMS

FeCl3, CH2Cl2,–78 C to rt

TsNHH

NBn

TMS

H61%

TsNHH

NBnH

Sarain A core

Al(Me)3 (3 eq.)CH2I2 (2 eq.),

CH2Cl2, rt OH71%

Price; JOC, 1993, 58, 3589–3590

Me

Me

Me

OR

A: Et2Zn, CH2I2, Et2O, rtB: iBu3Al, CH2I2, CH2Cl2, rtC: Sm/Hg, CH2IX, THF, –78 C to rt

Me

Me

Me

OR

Me

Me

Me

OR

Me

Me

Me

OR

R A B CH 74 1 98

Bn 97 67 75

2 76 0HBn 1 0 0

H 3 4 0Bn <1 0 0

Yamamoto; JOC, 1985, 50, 4412–4414Org. React. 2001, 58, 9

complementary to the usual

Simmons–Smith cyclopropanation

N

MeO2C

NBn

CO2Me

ClN

MeO2C

NBn

CO2Me

H

Hi. LDA, THF, –70 °Cii. HCl, rt

33%

Bosch; JOC, 1993, 58, 7756–7767

N

NH

OH

H

MeO2C H Me

O

N

NH

MeO2C H Me

OClhν,

MeOH–H2O, 15 min

55%N

HNH

MeO2C H Me

Et3N61%

Cl

OCl

N

NH

H

H

MeO2C H Me(±)-2,7-Dihydropleiocarpamine

1. Lawesson's reagent2. NiCl2, NaBH4, MeOH

N

NH

H

H

MeO2C H

O

Me

Et3SiH–TFA(50%)

(30 % 2 steps)

NiCl2

Back; JOC, 1993, 58, 2407–2413

Me

MeMe

Me

Me

HCl

NaSPhMe

HPhS

NiCl2, NaBD4,MeOD

LiBEt3D

Me

HD

NaBH4, ROH Ni2B + H2

RSR' Ni2B RH + R'H

Stereoretentive!

mild desulfurization conditions

OH

JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

OH

OH H

O BF3•Et2O, 23 °C

71% OH

HO

OBz

OH

HOBz

OO

Overman; JOC, 1993, 58, 2468–2477

NaOMe, MeOH

83%

O

OOHMeO2C

dr = 10–12:1H

H

O

O

H

HMe

BrHH

Br

(±)-kumausallene

R

OMeOOH Li MeMg(HMDs)2

2 x LiHMDs + MeMgCl

75%toluene R

MeOOH

NClR =

Weinreb's procedure provided the methyl ketone in 71 % yield, along with several impurities (0.5-1%) which were not

easily removed without a yield penalty

The new reagent provides clean product with complete suppression of impurities

Reider; JOC, 1993, 58, 3731–3735

R NH2

O PhI(OAc)2,KOH, MeOH R

HN OMe

OR = Alkyl, Ar, Het Ar

analogous to Curtius rearrangement

Moriarty; JOC, 1993, 58, 2478–2482

70–90%PhI(OAc)2

KOH,MeOH PhI(OMe)2

R N

OIPh

OMeR NH

OIPh

OMeMeO

C N R

–PhI–MeO– MeOH

RHN OMe

O

O

OH

O

AcO

HO AcOOBz

O

OMeO

Ph

NHBz

OCO2Bn

Me

O

AcO

AcOOBz

O

OMeO

Ph

NHBz

OCO2BnMe

MeMe

DAST,CH2Cl2

Chen; JOC, 1993, 58, 4520–4521

OTroc

O

HO

HO AcOOBz

O

OMeO

Ph

NHBz

OH

Me Et2NCF2CHFCl, CH2Cl2

(Yarovenko reagent)

OTroc

OHO AcO

OBz

O

OO

Ph

NHBz

OH

Me

OTroc

OHO AcO

OBz

O

OO

Ph

NHBz

OH

MeMe F

47%

13%

Chen; JOC, 1993, 58, 2927–2928

MeMe

MeMe

MeMe

NN

SO2Ph

SO2Ph

RM NHN

SO2Ph

NNR

SO2Ph

Padwa; JOC, 1993, 58, 2061–2067

BA

NaH 100 0MeMgBr 0 100nBuMgBr 0 100sBuMgBr 0 100PhMgBr 0 100tBuMgBr 12 88MeLi 50 50nBuLi 17 83sBuLi 67 33tBuLi 33 67

RM A B

DDQ

NNR

SO2Ph

possible method to get around alkylation selectivites

for pyrazoles?

esters to methyl ketones

OBz

Prins cyclisation – Pinacol rearragement

7 7

7–epi Taxol

19

80–90%

10

Et2N

F F

Cl

F

Yarovenko reagent

"relatively safe fluorinating agent that is easy to use"

–EROS

JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

OOBn

Me MeO

HOi. DDH, aq. MeCNii. CSA, CH2Cl2

75%, 15:1 dr

O

OO

OHOBn

Me MeOxidative rearrangement

Albizati; JOC, 1993, 58, 291–293

O

OO

MeO

MeMe

OMeTrioxa-Tricyclic Subunit

of Saponaceolides

O

Me

1. CH2(CO2Et)2, Na, EtOH2. KOH, HCl

O

MeOH

OPPA,

AcOH, 100 °C O

O

MeLDA (2 eq.),THF, –78 °C

O

Me

OFeCl3,

DMF, –78 °CO

Me

O

Me

HO1. THF–HMPA, –78 °C2. THF, 0 °C

Ph3P CH2

H2C CHMgBr

KHMDs,THF, Δ

OH

HMe

Paquette; JOC, 1993, 58, 4245-4253

H

H

H

MeMeO

H

H

H

H

MeMe H

CO2H

Me

N

S

O

OO

OMsMe

OTBDMSH

DMSO,rt, 3 h N

S

O

OO

XMe

OTBDMSH X = Cl, 90%

X = Br, 85%X = I, 75%

Altamura; JOC, 1993, 58, 272–274

O2N O2N

I

NIS, TfOH, rt, 86%

NIS, Ag(OTf), 150 °C; 45% F3CS

O

O OHI TfO

Olah; JOC, 1993, 58, 3194–3195

E1

E2

1. NaH2. CuX2, DMSO, 40 °C

X = Cl/Br

E

EX

E1/E2 = EWG

70–90%tolerates double and triple bonds along with allylic and benzylic moeities

Dai; JOC, 1993, 58, 4596–4598

Cerorubenic Acid-111

40%

61% (2 steps)

71% (2 steps)

80%

88%

CaX2,

for highly electron deficient aromatics

Bn2N CO2HBn2N

OsO4 (cat.)Jones reag.acetone/rt

Presence of basic nitrogen does not interfer withe the reaction.

Weinreb; JOC, 1993, 58, 4745

65%

Mildly acidic conditions – protection of basic nitrogen as ammonium salt

mild halogenation conditions

NH

NH

O

MeMe

O

DDH/DBH O

HO

O OMe

OBnMe

via

intramolecular oxidative coupling

applied to other allylic and benzylic systems

No need for chromatography

"very reactive superelectrophile"

"widely used as a disinfectant used for

drinking water purification"

JOC Year In Review: 1993Rohan MerchantBaran Group Meeting

04/18/2015

TMS

TMS

O

OTMS

TMS

O

O

IBuLi, TMEDA

90% 1. HCO2H, CuSO42. (MeO)2POCH2CO2Me, tBuOK

TMS

TMS

CO2MeAcO SiMe3

Pd(OAc)2, (iPrO)3P

TMS

TMS

CO2Me

KF, DMSO

[3+2]90%

95%

CO2Me 81%

5% CpCo(CO)2,136 °C, hν

TMS TMS

CO2MeTMS

TMS

decane, 175 °C

75%[2+2+2]

[4+2]

TMS

TMSCO2MeH

H

TMS

TMSCO2MeH

H

75%15%

Malacria; JOC, 1993, 58, 4298-4305 Some useful modifications

MeN Me

N

O OPh

OHi. 1, Additive, THFii. PhCHO N

LiPhPh

Me Me

N SHNBS, MeOH

N SOMe

O

H

H

O

SSPivO

H

H

O

SSPivO

74%

Trost; JOC, 1993, 58, 1579–1581

i. KH, THFii. 2, toluene, CuSO4, 110 °C

Additive ee (%)None 24LiCl (0.5 eq.) 78

1

Simpkins; JOC, 1993, 58, 533–534

2

Me

OHOH

AcCl (1.2 eq.), Base (2.0 eq.)CH2Cl2, –78 °C

Me

OHOAc

Yamamoto; JOC, 1993, 58, 3791-3793

Bulky bases (iPr2EtN or collidine) give better selectivity than Et3N, pyridine

N

O

OHO2C

NNHTs

DCC N

O

O

O

O

N2

RH = Ar/Alkyl amine, phenols, thiophenols, peptides

3,THF/DMFRH R

O

N2

Badet; JOC, 1993, 58, 1641–1642

3

Extends to other acyl chlorides and silyl chlorides as well

iPr2EtN 86 95.7:4.3collidine 92 98.5:1.5

base yield (%)

1° OAc: diacetate

Ph

O

O Ph

O

H

SnCl2•2H2OCH2Cl2, rt naphthalene; 53% (2 h)

C60; 63% (3 h)

Roskamp; JOC, 1993, 58, 4142–4143

no promoter; 38% (16 h)

enone formation while avoiding oxidation step

mild diazoacylating agent

79% (2 steps)

OH

bench stable

FYI!

retro 4π e-