Post on 12-Jun-2018
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 1
Statistics:Volume 59Issues 1-268315 pages
Publication Record:
Marshall, J A (13)Adam, W (10)Paquette, L A (10)Denmark, S E (9)Katritzky, A R (8)Padwa, A (8)Rapoport, H (8)Brown, H C (6)Danishefsky, S J (6)de Kimpe, N (5)
Ishii, Y (5)Kumar, A (5)Kurth, M J (5)Liebeskind, L S (5)Matsumoto, K (5)Miller, M J (5)Mori, M (5)Pettit, G R (5)Rozen, S (5)Sato, Y (5)
Notable Events of 1994:Jan 1st - AAPL was $1.04Jan 10th - Lorena Bobbitt's trial begins Mar 31st - Nature reports the finding in Ethiopia of the first complete Australopithecus afarensis skullApr 7th - Vatican acknowledges Holocaust for 1st timeApr 22nd - In Denmark the largest lollipop, weighing 3,011 pounds, madeMay 10th - Nelson Mandela sworn in as South Africa's 1st black presidentJun 15th - Ruth Bader Ginsburg, sworn in as Supreme Court JusticeJun 26th - 126°F (52.2°C) in Death Valley, CalifNov 9th - The chemical element Darmstadtium is discovered.
Top Songs:The Sign by Ace of BaseI Swear by All-4-OneI'll Make Love To You by Boyz II Men
Top Movies:The Shawshank RedemptionPulp FictionForrest Gump
Top 5 Most Cited Papers:
A Practical Method for the Large-Scale Preparation of [N,N'-Bis(3,5-di-tertbutylsalicylidene)-1,2-cyclohexanediaminato(2-)]manganese(III) chloride, a Highly Enantioselective Epoxidation CatalystJay F. Larrow, Eric N. Jacobsen, Yun Gao, Yaping Hong, Xiaoyi Nie, Charles M. Zepp642 citations
On the Nature of the "Copper Effect" in the Stille Cross-CouplingVittorio Farina, Suresh Kapadia, Bala Krishnan, Chenjie Wang, Lanny S. Liebeskind395 citations
Lanthanide Triflates as Water-Tolerant Lewis Acids. Activation of Commercial Formaldehyde Solution and Use in the Aldol Reaction of Silyl Enol Ethers with Aldehydes in Aqueous MediaShu Kobayashi, Iwao Hachiya345 citations
Acceleration of the Dess-Martin Oxidation by WaterStephanie D. Meyer, Stuart L. Schreiber328 citations
Cationic BINAP-Ru(II) Halide Complexes: Highly Efficient Catalysts for Stereoselective Asymmetric Hydrogenation of .alpha.- and .beta.-Functionalized KetonesKazushi Mashima, Koh-hei Kusano, Naomasa Sato, Yoh-ichi Matsumura, Kyoko Nozaki, Hidenori Kumobayashi, Noboru Sayo, Yoji Hori, Takero Ishizaki288 citations
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 2
Select Natural Products Isolated Pentalenene104, Burnell
MeMe Et Me
Me Et
OO
MeMe Et
O O(CH2OH)2p-TsOH BF3•Et2O OMe
MeMe
EtO
OMe
MeMe
H
H
4 steps H
H
+ diast.
KOtBu
Me
+ diast.Me
Me
MeH
H
MeH3 steps
pentalenene
OTMSTMSO
CC-1065 (protected A unit)192, Tietze
NH
N
O
NHN
Me
O
OMeOH
O
NH
NH
OMe
OH
O
H2N
AB
C
Br
OBn
NH2
Br
OBn
N SO2Ph1. PhSO2Cl/py
2. NaH, allyl bromide
- first synthesized by Boger et al. (1992)- cancer tissue pH ~6.2; normal tissue pH ~7.2
"...we have become interested in highly toxic compounds which can be detoxified by the formation of derivatives which may be cleaved at pH 6.2 with liberation of the toxin."
Zr
OBn
NSO2Ph
H3CCp Cp
OBn
NSO2Ph
ZrCp
Cp
-CH4
OBn
ZrCp
Cp N SO2PhI2
OBn
N SO2PhI
I
45%10% byproduct (can be recycled)
tBuLi,Cp2Zr(CH3)Cl
O
I
OBn
N SO2Ph6 steps
mech.?OMe
Me
N SMe
H Hcuracin A O
O
O O
Me HOH
(−)-prehalenaquinone
HNN
N
NHNH
N
NH
O
OO
O O
OO
MeMe
OHMe
NHHO
phakellistatin 3
MeNO
NH
OO
O OHMe
Me
Me
Me MeI
HO
doliculide
NNH
N
O
O
OHMe
MeOOH
H
H H
H
H
bioxalomycin α1
O
HO
Me
Me
MeHO Me
heliannuol BO O
O
OH
OO
O
Sch 49209
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 3
OBn
N SO2PhI
OAc
NAc OBn
N SO2Ph
OAc
OBn
N SO2Ph
OAc
N NAc
Me
Ac
Heck Rxn
a or b
a. Pd(OAc)2, NaOAc, NBu4Cl, DMFb. Pd(PPh3)4, NEt3, CH3CN
64%10%
30%70%
O
NSO2Ph
NH
Me
see Boger et al. JACS, 1988, 4796.
Pseudopterane 2,5-Furanocyclic Ring System324, Marshall
O
MeMe
O O
MeMe
HO
H H
HO
MeMe
HO
H H
H70:30
O
MeMe
HOH
H3 steps
O
MeMe
O
MnO2
O
MeMe
HOH
H
trans-isomer
cis-isomer
Core Ring System of the Cyathins885, Paquette
O
S
S O
S S120º C, cat. Et3N
OO
5 StepsKH18-cr-6;
NH4Cl,H2O
OH
MeMe
OO
O
Me Me
Aspicilin949, Sinha and Keinan
OO
O
O MeMe
MeMe
OO
O
O MeMe
MeMe
OMEMOH
OO
O
O MeMe
MeMe
OMEM
EtO2C
OO
Me
OAc
MeMe
OMEM
EtO2C
OHOH
OHO
OMe(+)-aspicilin
1. AD-mix-β
2. (CH3)2C(OMe)2
AD-mix-α
then3 steps
most reactive
equally reactive
AD-mix regioselectivity: Once A is dihydroxylated,B is much less reactive than C
CB
AA
A
A
"Stellatrienes"1027, Gleiter
2 steps
3 steps 3 steps
"In these cases, not only the possible interactions but also the beauty of the molecules1 initiated our studies."
1J. Aestetics Art Criticism 1990, 48, 191.
Examples:
"Key Reactions":
RO RO
hv
OR
baseO
CHR2
HO
RRIntramolecular Paterno-Büchi Base-induced cleavage
O
MeMe
O
OMe
OH
Kallolide A
O
MeMe
HO
Previous strategy:
OH
Me
S
SClMeO
OMe SHSH
HCl S
S HCl
MeLi
Synthesis of inverse demand Diels-Alder coupling partner:
OO
OH
MeMe
OO
OH
MeMe
via:
A B
BuLi
BuLi
HH
E (40%)Z (60%)
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 4
O
hv
O• [4+2]
O HO
OHO
DATMP
1. (COCl)2, DMSO2. Et3N
iPrLiMsCl,Et3N
name?
Angularly Fused Triquinanes 1396, Clive
RB
AX
B
AXR
OH
B
A R
H
B
R
H
A
General Scheme:
Co2(CO)8NaBH4,CeCl3 Bu3SnH
A or B = heteroatom; X = Br or SePh; R' = Me or H
O
Ph
H
O
Ph
OH
Ph
H
O
AcN
Ph
HOH O
Ph
OH
Me Me
OHOH
X
OH OHR'
no NaBH4/CeCl3;trans pdt observed
2-Azetines 1608, Marchand, Bott, and Archibald
OHHONH2
1. HOAc
2. HBr, HOAc3. KOH N
Et
N
Et
N2O4(various
conditions) NH2
Et ONO2
N
Et ONO2
N
Et ONO2
NO
NO2
N
Et ONO2
N
Et
NO
ClCO2Et
Ms2O
ClCO 2 Et
ClCO 2 Et
Tf2O
N
Et Cl
CO2Et
N
Et OMs
Ms
NTf
NTf
O
NTf
NOHO3 NH2OH
NMs
EtKOtBu
NMs not formed
NNO2
Et4 steps
Tetranitrotoluenes 1714, Nielson and Wilson
MeNO2
NO2O2NNO2
MeNO2
NO2NO2
MeNO2
NO2O2N
O2N O2N
MeNO2O2N
NO2
TNT
all slightly more dense than TNT due to presence of additional nitro group
MeNO2
NH2
O2N
MeNO2
NHNO2
O2N
MeNO2
NH2
O2N
1 2 3
HNO3
HOAc/Ac2OH
H2SO4H2S2O8
NO2
1
name?
MeNH2
NO2
O2N NO2
MeNO2O2N
NO2
O2NMe
N2
NO2
O2N NO2
O2NH3PO2
3 steps ONOSO3H
H2SO4
density (g/mL): 1.701 1.69 1.66 1.65
Me
favored by 12 kcal/mol
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 5
Sophoradiol2324, Johnson
F
TMS
F
TMS
HO
O
H
Me MgBr
MgBr2F
TMS
Br
F
TMS
CO2Et
F
TMS
CO2Et
Me
MeCO2Et
tBuOK
F
TMS
MeLi
TFA•
H
H
F
H
3 steps
"...first examples of nonenzymic, biomimetic polyene pentacyclizations..."
controls regiochem
controls D/E cis-syn configuration
terminates cyclization
H
H
H OH
SophoradiolHO
Strychnine2685, Rawal
N
O
O
H
HH
N
CN
NO2
5 steps
NH2
N CO2Me
N
N CO2Me
MeO2C CO2Me
MeO2C CHO
Me
then ClCO2Me, PhNEt2
N
N
HCO2Me
CO2Me
185 ºC
N
HN
H
CO2Me
O
TMS-I;
MeOH quench, ΔN
N
H
O
I
OTBS
I OTBSBr
N
O
HH
N
OH
isostrychnine strychnine
"ethanolic potash"
Rubrolone C Ring3453, Boger
O
Br Br
O
Br
O
Br O
O
Et3NO
O
CuCNLi22
O
O
O
DBU
O
OMe
Me
25 ºC, 15 minO
OO
OO
MeMe
HH
HH
exo transition state
O
O
OO
O
MeMe
H
H
O
O
O OHO
Me MeOH
1. NBS, H2O2. KOtBu
HO
O
OHHO
O
O
OHHO1. LiOH
2.NBS, Ph3P3. Zn, NH4Cl
MnO2
This space is intentionally left blank.
LDAK2CO3
1. Pd(OAc)2, Bu4NCl, K2CO32. HCl
MeHO Me
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 6
Cyclic Enol Ethers via Mo RCM4029, Grubbs
MoN Me
Ph
MeRORO
i-Pr i-Pr
R = CMe(CF3)2
OR1
O
OH HO OH
CO2Me
O
O
7 steps OO
O
Me
O
RO OR
R = CH2Ph
OO
O
Me
RO OR
Me
12 mol % [Mo] cat.
O
O
O
RO OR
O
O
O
HO OH
H2, Pd/C
CH3CHBr2,TiCl4, Zn,
TMEDA,cat. PbCl2
72%
n OR1n
R2
nOR1
General Scheme:
O nR1
O
O nR1
R2
OR1
n
Molybdenum Catalyst
R1 = H, Me; n = 1,2
Some Products:
Benzofuran NP Synthesis:
O
O O O
OPh
O Ph PhPh
Ph
Phn-Pr
Ph
Thiangazole4733, Heathcock
HN N
H
HN CO2MeCbz
O
OMe Me
Me
SBn
SBn
SBn
3 steps HN N
H
HN CO2H
O
OMe Me
Me
SBn
SBn
SBnO
Ph
Me
O
NHMe
OBn
H3NClHN N
H
HN
O
OMe Me
Me
SBn
SBn
SBnO
Ph NH
OMe
NHMe
O
OBn
N S
NHO
NS
N
SPh
MeHN
O
MeOH
Me
Me
Me
N S
NHO
NS
N
SPh
MeHN
O
MeO
Me
Me
Me
1. Na, NH32. NH4Cl3. TiCl2
N S
NS
N
SPh
Me
Me
MeO
N
Me
O
MeHN
N S
NS
N
SPh
Me
Me
MeO
N
Me
O
MeHN
DMP p-TsOH DDQ
Camptothecin5120, Comins
(−−n I)-thiangazole
N OMe
1. MesLi
2.
3. n-BuLi
N NMe
MeMe
CHO
N OMe
Li N
OLiMe
NMeMe
1. CeCl3
2.
3. H3O
CO2Me
O
Et
N OMe
OMeO2C
EtOH
N OMe
O
OEt
HO
NH
O
O
OEt
HO
(i-PrO)3Al
N Br
OH
N
O
O
OEtHO
N Br
N
O
O
OEtHO
N
Pd(OAc)2
(±)-camptothecin
1N HCl
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 7
Silphiperfol-6-ene and Methyl Cantabradienate5419, Snider
Me
CHO
Me
N Ot-Bu
O
t-Bu
CHO
Me
Me
MgBr1. PDC2. (COCl)2
Me
Me
OCl
DMAP, Et(i-Pr)2N
Me
Me•
O
[2+2]Me H
MeO
LiMe H
MeHO
Me H
Me
O
Mn(pic)3
MeLi
Me H
Me
HO Me
Na, NH3/EtOH
Me H
MeMe
Me
Me H
Me
TfO
KHMDS, PhN(Tf)2
Me H
Me
MeO2C
1. [Pd], CO
2. CH2N2
Grayanotoxin III5532, Matsuda and Shirahama
Me
OHTsO
MeO2C
Me
BnO6 steps
OTMS1. Δ,
2. 10% HF3. PDC MeO2C
Me
BnOH
H
O
4 stepsO
Me
O OH
H
O
Me
O O
H
HO Me
O
Me
O OH
H
O Me
SmI2
NaAuCl4•H2O
O
Me
O OH
H
Me
OH
OR
H
MeOR
SPh
10 steps1. n-BuLi
2. (PhS)2
O
MeMe
OMPM
ORMe
OR
SPhH
MeMe
MPMO
OHOR
MeOR
SPhH
MeMe
O
TBDMSO
H3 steps
ORMe
OR
H
MeMe
TBDMSO
OH
H
SmI2
ORMe
OR
H
MeMe
HO
O
HMe OR
R = MOM
7 steps
O H
ORMe
OR
SmI2
MeMe
HO
HOOH
MeHH OR
OHMe
OHMe
Me
HO
HOOH
MeHH OH
3 steps
silphiperfol-6-ene
methyl cantabradienate
(−)-grayanotoxin III
This space is intentionally left blank.
JOC Year in Review: 1994Baran Group Meeting Leah Simke
Page 8
Illudin M6965, Kinder
Me
O ON2
MeMe
O
BrMe O
MeMeO
Br
O
Me OMeMe
Br
O
HOMe
MeMgBr KOH/MeOH
Me OMeMe
MeHO
OMeOH
Me OMeMe
MeHO
O
CrO3/H2SO4
Rh2(OAc)4
Me OHMeMe
MeHO
OH
LAHNBS
pyridine
Me OHMeMe
MeHO
O(±)-illudin M
Me OMeMe
MeHO
OH
LAH
Also, taxol.