內(nèi)容手性的記憶

OO

KH(2eq),MeI(2018-crown-6(2solvent,–78to–20

MeOPh

O93%

THF:48%,66%toluene:54%,73%OO

HOHHOH

R1

R3N

O O

N

R3

≡

ON

R1 R1NR2

base(1.1-1.8–78oC,30-60MeI,–78oCtort

yield ee123456tCO22 CO 2a1-AdamantylbTheamountofbaseusedwas2.4

A

O

N

C

22B

D

MeN

96%

LTMP(1eq),–78MeI(10eq),–78

26%(74% MeN

30%

2CO2

G?？

2 2

N

–78oC,

–78

ln

0

1500t(min)tt1/2(–78oC)=22t1/2(20oC)=<0.1=16.0kcal/mol(–78

base(1.2eq)solvent,temp.

temp.timeyieldee198289324747751146141791877982T.Kawabata,S.Matsuda,S.Kawakami,D.Monguchi,K.Moriyama,J.Am.Chem.Soc.2006,128,15394-OONOOHM+OONOOH

N

2(M=K,

N

CN N (M= O

O

Li:(inversion) Na,K:塩基，Boc 1

solvent,

2

base

temp. time yield ee1KHMDS2KHMDS03KOHa24KOHa25LiOHa~0–6NaOHa27CsOHa28KOHa1%H2Oin29KOHa10%H2Oin1KOHa20%H2Oin1aPowderedmetalhydroxidewasbNumbersintheparenthesesindicatethepercentrecoveryof(entry8-10)DMSO中ではKOHは塩基性が強い

powdered

NRN

N()4

DMSO,20

RXtimeyieldee12344I25I86I3(X=Br→I)

20oC,5

NNNNNXONHOKXHaxiallychiral

concertedSEiN

LDA(1.2eq),HMPA(6 THF,–78oC,15BuLi(1.2eq),15E-X(10eq),0.5-10NH4Cl

NE 1 (±)- 1 (±)-2(+)-973(+)-954(+)-5(+)-6D(+)-997958(+)-aElectrophilesused:BnBr,4-MeC6H4CH2Br,2-PhC6H4CH2Br,bromide,D-OTFA,bRacemic6isalsoobtainedifBnBrisaddedonly10secondsafterdeprotonationbyLDA.HNHNNRG≠HO

HONONRNH RG≠1H234aEnantiomerizationbarriersG≠determinedby1HNMRspectroscopy.Rが小さいと，ΔG?(R=H,Me,iPr) HOHON G≠=22.2

NO

Boc

(P)Erel=0

(M)Erel=2.6Erel=relativeenergywithrespecttothemoststableONONNOONO

temp.yield 1 2 3 93:74 7:935 19:8160 17:8370 28:728 86:14KHMDS,NaH,t-BuOK,DMAPONON O

N

O(P)conformerof(3S)-13

O

NONNONON

OORRRHRNNNONO(M)conformerof(3S)-13

(3R)-R=SiMe3,S= A≠

AOBAOB

low

AOBAOB-amino AOBAOB

R1

-aminoAr-CO→M/PN-CO→cis/trans

KHMDS,–78oC,8–78oC,10

R O O

O O

E=CH2CO2Et:80%,96%eeE=Et:59%,91%ee

E=CH2CO2Et:94%,91%eeE=Bn:82%,82%ee

E=CH2CO2Et:85%,89%eeE=Me:88%,75%eeO O

S( E=CH2CO2Et:96%,94%E=allyl:88%,90%

E=CH2CO2tBu:75%,91%E=allyl:85%,89% H

+ +

Retentionof (P,cis,

E+(P,NOHRONOHRO

NONO

Inversionof(M,cis, (M,

NO

O

Otemp.yieldee1ITol:THF=2.52Tol:THF=436465106Tol:THF=127Tol:t-Pr2O=128Tol:t-BuOMe=129Tol:i-Pr2O=12Tol:t-BuOMe=12aI:15wastreatedwithKHMDS(1.1eq)for30min,thenwithPhCHO(3.0eq)for2h.II:Asolutionof15wasaddedtoasolutionofPhCHO(3.0eq)andKHMDS(1.1eq).III:KHMDS(