Addition of Allylic Boronates to Carbonyl Derivatives...

Addition of Allylic Boronates to Carbonyl Derivatives

Yuta Takenouchi

Contents

γ-alkoxyallylboronates (1981)

L.A. catalyzed allylation (2002)

R. W. Hoffmann

D. G. Hall

H. C. Brown

W. R. Roush

diisopinocampheylboranes (1983)

BR1

R2

BR1

R2

O

OCO2

iPr

CO2iPr

Tartaric acid esters (1985)

B

RO

HOR

OR

Sc(OTf)3

BMeO O

OⅠ. Introduction 　- Character of allylboronates 　- Mechanisms for diastereoselectivity

Ⅱ. Asymmetric allylboration

Ⅲ. Lewis acid catalyzed allylboration 　

Ⅳ. Recent researches

Ⅰ. Introduction 　- Character of allylboronates 　- Mechanisms for diastereoselectivity




C‒C bond formation

Allylation of Carbonyl Groups

BrPhCHO

Ph

OH

Cr(II) salt.

>95:5 dr

R1

OH

R2 R3

O

R1

OH

R2 R3

MLn

R1 H

O

R1

OH

R2 R3

H

OR1

OH

R2 R3

O

O

R1

O

R2 R3

aldol reaction product

Okude, Y.; Hirano, S.; Hiyama, T.; Nozaki, H. J. Am. Chem. Soc., 1977, 99, 3179–3181

Yamatnoto, Y.; Yatagai, H.; Naruta, Y.; Maruyama, K. J. Am. Chem. Soc.1980, 102, 7107-7109

Hoffmann, R. W.; Zeiss, H. J. Angew. Chem. Int. Ed. 1979, 18, 306–307.

B(pin)PhCHO

Ph

OH

96:4 dr

Sn(n-Bu)3PhCHO

Ph

OH

BF3·OEt2

>90:10 dr

▪Diastereoselective allylation▪C‒C bond formation with allylmetals

▶ Developed since the 1970’s

Blais, J.; l'Honore, A.; Soulié, J.; Cadiot, P. J. Organomet. Chem. 1974, 78, 323–337.Li, Y.; Houk, K. N. J. Am. Chem. Soc. 1989, 111, 1236–1240.

Brown, H. C.; Racherla, U. S.; Pellechia, P. J. J. Org. Chem. 1990, 55, 1868–1874.

▪Allyl silane, Allyl tin reagents

SiMe3R1

O

R2

TiCl4 OH

R1 R2

SiMe3

OH

R1 R2

櫻井-細見反応

Allylation with Allyl Metal Reagents

MLnR1

R3O

H

R2

R3

OH

R1 R2R3 H

O

R1

R2

MLn

L.A.

MgBrLi

▪Allyl lithium, allyl Grignard reagentsProblems ▶stability of reagents ▶α,γ-regioselectivity

Closed Transition State Open Transition State

✓ no added Lewis acid necessary ✓ proceed via rigid chair-like T. S. ✓ diastereospecific, diastereoselective

✓ require Lewis acid activation ✓ proceed via open T. S. ✓ not diastereospecific

MLnR1

R3O

H

R2

R3

OH

R1 R2R3 H

O

R1

R2

MLn

L.A.

Allylation with Allylboronates

Hoffmann, R. W.; Niel, G.; Schlapbach, A. Pure Appl. Chem. 1990, 62, 1993–1998.Gennari, C.; Fioravanzo, E.; Bernardi, A.; Vulpetti, A. Tetrahedron 1994, 50, 8815–8826.

Omoto, K.; Fujimoto, H. J. Org. Chem. 1998, 63, 8331–8336.Pietruszka, J.; Schöne, N. Synthesis 2005, 2006, 24–30.

▪Allylation with allylboronates (allylboration)

B

RO

H

R

OOR

OR

B(OR)2

R

O

H

B(OR)2

R

OHH+

Boration

Allylation

Closed Transition State Open Transition State

activation of the carbonyl group

✓ no added Lewis acid necessary ✓ proceed via rigid chair-like T. S. ✓ diastereospecific, diastereoselective

✓ require Lewis acid activation ✓ proceed via open T. S. ✓ not diastereospecific

Reactivity of Allylboronate Reagents

Kramer, G. W.; Brown, H. C. J Organomet Chem 1977, 132, 9–27.Hoffmann, R. W.; Zeiss, H. J. J. Org. Chem. 1981, 46, 1309–1314.

Brown, H. C.; Jadhav, P. K.; Bhat, K. S. J. Am. Chem. Soc. 1985, 107, 2564–2565.Ramachandran, P. V.; Pratihar, D.; Biswas, D.; Srivastava, A.; Ram Reddy, M. V. Org. Lett. 2004, 6, 481–484.

▶Low Lewis acidity of boronates

▶ Lower reactivity

BOR

ORR2

R1

R3

Sterically hindered R

EWG (eg. CO2R)

BOR

ORallylboronates

(11B σ~30 ppm)allylboranes

(11B σ~70 ppm)

BR

RLewis acidity

Nucleophilicity

B RR

B BO

OBO

O

Isomerized at rtB-crotyl-9-BBN Pinacol crotylboronate

Easy preparation of E or Z isomer

B(pin)

RR

RO

B O

O

PhH

A1,3-strain

H

R

Impact of Substituent at α-Position

Tsai, D. J. S.; Matteson, D. S. Organometallics 1983, 2, 236–241.Hoffmann, R. W.; Dresely, S. Tetrahedron Lett. 1987, 28, 5303–5306.

Hoffmann, R. W. Pure and Applied Chemistry 1988, 60, 123–130.Carosi, L.; Lachance, H.; Hall, D. G. Tetrahedron Lett. 2005, 46, 8981–8985.

Fang, G. Y.; Aggarwal, V. K. Angew. Chem. Int. Ed. 2007, 46, 359–362.Althaus, M.; Mahmood, A.; Suárez, J. R.; Thomas, S. P.; Aggarwal, V. K. J. Am. Chem. Soc. 2010, 132, 4025–4028.

BOPhR

O

OH

gauchestrain

R

RO

B O

O

PhH

H

R

(Z)BOPh

RO

OH

R(E)

▶ Diastereoselectivity is determined by gauche strain vs A1,2-strain

R H

O

R

R Ph

OH

R

(E)

R

R

Ph

OHR

(Z) R

R

R

R

R

R H

O

R

OB

O

OB O

OB O

PhPh

PhPh

E/Z>99:1

E/Z30:70

E/Z1:>99

Small

Large

(pin)B

R(pin)B R

BOPh O

OH

Me

HBOPh O

OH

Me

H

Impact of Substituent at γ-Position

Hoffmann, R. W.; Zeiss, H. J. Angew. Chem. Int. Ed. 1979, 18, 306–307.Hoffman, R. W.; Weidmann, U. J. Organomet. Chem. 1980, 195, 137–146.

Hoffmann, R. W.; Zeiss, H. J. J. Org. Chem. 1981, 46, 1309–1314.Hoffmann, R. W. Angew. Chem. Int. Ed. 1982, 21, 555–566.

Roush, W. R.; Ando, K.; Powers, D. B.; Palkowitz, A. D.; Halterman, R. L. J. Am. Chem. Soc. 2002, 112, 6339–6348.

BOPh O

OH

Me

H

BOPh O

OH

Me

H

R

R

RR

RRH

O

R

R

R R

RR

▶ Diastereoselectivity is determined by E/Z in allylboronates

(Z)(E)(R)(R)

(R)(R)OH

PhMeR

R(S)(S)

Me(R)(R)

OH

PhR

RRH

O

R

anti syn

= Ph

R

R

= Me

R (S)(S)

OH

R (R)(R)

OH

Impact of Chiral Auxiliaries in Allylboration

Brown, H. C.; Bhat, K. S. J. Am. Chem. Soc. 1986, 108, 293–294.Stürmer, R.; Hoffmann, R. W. Synlett 1990, 1990, 759–761.

Roush, W. R.; Grover, P. T. Tetrahedron Lett. 1990, 31, 7567–7570.Barrett, A.; Malecha, J. W. J. Org. Chem. 1991, 56, 5243–5245.

Roush, W. R.; Gover, P. T.; Lin, X. Tetrahedron Lett. 1992, 48, 1981–1998.Hunt, J. A.; Roush, W. R. J. Org. Chem. 1997, 62, 1112–1124.

Roush, W. R.; Pinchuk, A. N.; Micalizio, G. C. Tetrahedron Lett. 2000, 41, 9413–9417.

+

50 : 50

B O

OB O

O

B O

OCO2

iPr

CO2iPr

94 : 6

R H

O

R

O

B O

O

R

H

R

O

O B

O

H

R

OH

Rracemic

R R

R R

(R)-isomer : (S)-isomer

(R)-isomer : (S)-isomer

1 : 99(R)-isomer : (S)-isomer▶B-chiral allylboronates: require stoichiometric amount of chiral auxiliary

▶C-chiral allylboronates: few catalytic synthetic methods are available

B-chiral

C-chiral

B O

O

Cl

Allylboron Compounds with Chiral Auxiliaries

Herold, T.; Hoffmann, R. W. Angew. Chem., Int. Edit. 1978, 17, 768–769.Haruta, R.; Ishiguro, M.; Ikeda, N.; Yamamoto, H. J. Am. Chem. Soc. 1982, 104, 7667–7669.

Brown, H. C.; Jadhav, P. K. J. Am. Chem. Soc. 1983, 105, 2092–2093.Roush, W. R.; Walts, A. E.; Hoong, L. K. J. Am. Chem. Soc. 1985, 107, 8186–8190.

Garcia, J.; Kim, B. M.; Masamune, S. J. Org. Chem. 1987, 52, 4831–4832.Reetz, M. T. Pure and Applied Chemistry 1988, 60, 1607–1614.

Roush, W. R.; Banfi, L. J. Am. Chem. Soc. 1988, 110, 3979–3982.Short, R. P.; Masamune, S. J. Am. Chem. Soc. 1989, 111, 1892–1894.

Corey, E. J.; Yu, C. M.; Kim, S. S. J. Am. Chem. Soc. 1989, 111, 5495–5496.Roush, W. R.; Grover, P. T. J. Org. Chem. 1995, 60, 6641–6641.

Burgos, C. H.; Canales, E.; Matos, K.; Soderquist, J. A. J. Am. Chem. Soc. 2005, 127, 8044–8049.Canales, E.; Prasad, K. G.; Soderquist, J. A. J. Am. Chem. Soc. 2005, 127, 11572–11573.

Hoffmann, 1978 Yamamoto, 1982 Roush, 1985

Corey, 1989

Brown, 1983 Roush, 1988 Masamune, 1987

BR1

R2

O

O

PhBR1

R2

O

OCO2

iPr

CO2iPr

BR1

R2

N

NPh

Ph

Ts

Ts

BR1

R2

BR1

R2

O

O N

N

O

OBn

Bn BR1

R2 Me

Me

R1 and/or R2 = H or Me

Soderquist, 2005

BTMSR2

R1

Roush’s Allylboration

Gung, B. W.; Xue, X.; Roush, W. R. J. Am. Chem. Soc. 2002, 124, 10692–10697.Roush, W. R.; Banfi, L. J. Am. Chem. Soc. 1988, 110, 3979–3982.

B O

OCO2

iPr

CO2iPr B3LYP/6-31G*

energy difference: 1.75 (kcal/mol)

B-O+

R

OO

O O iPr

OO

iPr

Favored TS

vs ≡

Electrostatic repulsion

Stabilized by no‒p*c=o interaction

BR1

R2

O

O N

N

O

OBn

Bn

B3LYP/6-31G* energy difference: 2.14 (kcal/mol)

B

RO

HO

O CO2iPrO

OiPr

TS A'

H

OR

BO

O

iPrO2C

O

iPrO

TS B'

Improved chiral auxiliary

Discovery of Lewis Acid Catalyzed Allylboration I▪First Lewis acid catalyzed allylboration

Hoffmann, R. W.; Krüger, J.; Brückner, D. New J. Chem. 2001, 102–107.Kennedy, J. W. J.; Hall, D. G. J. Am. Chem. Soc. 2002, 124, 11586–11587.

Kennedy, J. W. J.; Hall, D. G. J. Org. Chem. 2004, 69, 4412–4428.Siu Hong Yu; Ferguson, M. J.; McDonald, R.; Hall, D. G. J. Am. Chem. Soc. 2005, 127, 12808–12809.

Elford, T. G.; Arimura, Y.; Yu, S. H.; Hall, D. G. J. Org. Chem. 2007, 72, 1276–1284.Ramachandran, V. P.; Pratihar, D.; Biswas, D. Org. Lett. 2006, 8, 3877–3879.

Ramachandran, P. V.; Pratihar, D. Org. Lett. 2007, 9, 2087–2090.

MeO2CB O

O

R

(pin)BO CO2Me

H OTf

RCHO (2.0 equiv)TfOH (20 mol %)toluene, 0 ºC, 16 h

RH

MeO O

H MeHR

MeO O

H Me

O

O

R57%, >19:1 dr

R =

OMeMeO

MeO

Br

▪First Brønsted acid catalyzed allylboration

B(pin)RCHO (1.5 equiv)Sc(OTf)3 (10 mol %)toluene, rt, 24 h

Me

R = c-C6H532% yield

Bu

CO2EtO

O

BuMeR

R

OH

Bu Me

CO2Et

R = n-butyl62% yield

Discovery of Lewis Acid Catalyzed Allylboration II

▶ Improvement of reactivity and diastereoselectivity

Ishiyama, T.; Ahiko, T.-A.; Miyaura, N. J. Am. Chem. Soc. 2002, 124, 12414–12415.Lachance, H.; Lu, X.; Gravel, M.; Hall, D. G. J. Am. Chem. Soc. 2003, 125, 10160–10161.

Ramachandran, P. V.; Pratihar, D.; Biswas, D. Chem. Commun. 2005, 1988–1989.

B(pin) PhCHOLewis acidtoluene–78 ºC, 4 h

Ph

OH

MenoneAlCl3Sc(OTf)3

trace92% yield94% yieldMe

B(pin)

Me

or or

Ph

OH

Me

anti = 99%anti = 99%

noneAlCl3Sc(OTf)3

trace87% yield89% yield

syn = 98%syn = 98%

B(pin) Et2AlCl/(S)-BINOLtoluene–78 ºC, 4 h

Ph

OHMe

Me

40% yield51% ee99% anti

+PhCHO

▶ Moderate enantioselectivity

▪Impact of Lewis acid in allylboration

▪Chiral diol/Lewis acid combination catalyst

OHOH

(S)-BINOL

Mechanism of Lewis Acid Catalyzed Allylboration

R = pinacolato L.A. = AlCl3 TS energies (kcal/mol) B3LYP/6-311G

OR

O BOR

H

Ph

OR

O BOR

H

Ph

L.A.

+30.1+23.8

+6.3 +12.5OR

O BOR

H

Ph

L.A.

OR

O BOR

H

Ph

L.A.

background reaction (D)

pseudoequatorial boronate activation (A)

pseudoaxial boronate activation (B)

aldehyde activation (C)(A) (B)

(C)(D)

Omoto, K.; Fujimoto, H. J. Org. Chem. 1998, 63, 8331–8336.Rauniyar, V.; Hall, D. G. J. Am. Chem. Soc. 2004, 126, 4518–4519.

Sakata, K.; Fujimoto, H. J. Am. Chem. Soc. 2008, 130, 12519–12526.

B

PhCHO

+ Ph

OHwith and withoutSc(OTf)3

–78 ºC

▶ No rate acceleration with Sc(OTf)3

▪Calculated T.S. energies

▪Lewis acid catalyst with alkyl borane reagents

Development of Chiral Lewis Acid Catalysts I

HO OH8 8

(R,R)-Vivol

Kazuaki Ishihara; Shingo Nakamura; Masanobu Kaneeda, A.; Yamamoto, H. J. Am. Chem. Soc. 1996, 118, 12854–12855.Rauniyar, V.; Hall, D. G. Angew. Chem. Int. Ed. Engl. 2006, 45, 2426–2428.

Rauniyar, V.; Hall, D. G. Synthesis 2007, 2007, 3421–3426.Rauniyar, V.; Zhai, H.; Hall, D. G. J. Am. Chem. Soc. 2008, 130, 8481–8490.

Rauniyar, V.; Hall, D. G. J. Org. Chem. 2009, 74, 4236–4241.

B(pin)(10 mol %)

Na2CO3 (0.2 equiv)4 Å MS, toluene, –78 ºC, 12 h

R

OH

+

RCHO

OSnCl4

O HH

76–90%, up to 80% ee(R = aryl, alkyl)

B(pin) diol (5 mol %)SnCl4 (3.8 mol %)

Na2CO3 (0.1 equiv)4 Å MS, toluene, –78 ºC, 4 h

OH

+

(R,R)-Vivol(R,R)-F-Vivol

PhCHO

Ph99%, 85% ee95%, 96% ee

▶ Achievement of enantioselective allylboration

(R,R)-F-Vivol

HO OH8 8

FF

Development of Chiral Lewis Acid Catalysts II

T Robert Wu; Lixin Shen, A.; Chong, J. M. Org. Lett. 2004, 6, 2701–2704.Sha Lou; Philip N Moquist, A.; Schaus, S. E. J. Am. Chem. Soc. 2006, 128, 12660–12661.

Paton, R. S.; Goodman, J. M.; Pellegrinet, S. C. Org. Lett. 2008, 11, 37–40.Barnett, D. S.; Moquist, P. N.; Schaus, S. E. Angew. Chem. Int. Ed. Engl. 2009, 48, 8679–8682.

Jain, P.; Antilla, J. C. J. Am. Chem. Soc. 2010, 132, 11884–11886.Chen, M.; Roush, W. R. J. Am. Chem. Soc. 2012, 134, 10947–10952.

B O

OPh

OH

PhCHO (1.2 equiv)

(R)-TRIP-PA (5 mol %)toluene, 0 ºC, 16 h

MeMe

Ph

OH

Me

or

B O

O

Me

syn

anti

or

95% yield99% ee96% de


O

OP

O

OH

i-Pri-Pr

i-Pr

i-Pr

i-Pri-Pr(R)-TRIP-PA

▪Asymmetric allylation of Ketone

BO

OPh

OH

(S)-cat. (4 mol %)tBuOH, rt, 24 h

Me

Ph

OH

Me

or



BO

Oor

Ph Me

OMe

Me

(S)-cat.

OHOH

Br

Br

▪Enantio- and diastereoselective allylation

Sebelius, S.; Szabo, K. J. Eur. J. Org. Chem. 2005, 2005, 2539–2547.Cmrecki, V.; Eichenauer, N. C.; Frey, W.; Pietruszka, J. Tetrahedron 2010, 66, 6550–6564.

Chen, J.; Scott, H. K.; Hesse, M. J.; Willis, C. L.; Aggarwal, V. J. Am. Chem. Soc. 2013, 135, 5316–5319.Chen, J. L. Y.; Aggarwal, V. K. Angew. Chem. Int. Ed. Engl. 2014, 53, 1–6.

Allylation with in situ Generated Borinic Esters

O

B

HPh

i-Pr

H

B(pin)

32 ppm (11B NMR)

i-Pr

n-BuLi

–78 ºC15 min

B

7 ppm (11B NMR)i-Pr

O

O

Bu

Li

B

51 ppm (11B NMR)i-Pr

BuTFAA

–78 ºC30 min

O

BOH

i-Pr

Ph

rt14 hPhCHO

Bu

OOTFA

O

O

Phi-Pr

OB O

O

21 ppm (11B NMR)

Phi-Pr

OBO

OTFA

33 ppm (11B NMR)

Bu

–78 ºC30 minPhCHO

OTFA

68% yieldE/Z = 26:7494% ee

68% yieldE/Z = >99:190% ee

92% ee

Pd-catalyzed Asymmetric Diboration

Pelz, N. F.; Woodward, A. R.; Burks, H. E.; Sieber, J. D.; Morken, J. P. J. Am. Chem. Soc. 2004, 126, 16328–16329.Angela R Woodward; Heather E Burks; Louis M Chan, A.; Morken, J. P. Org. Lett. 2005, 7, 5505–5507.

Burks, H. E.; Liu, S.; Morken, J. P. J. Am. Chem. Soc. 2007, 129, 8766–8773.Burks, H. E.; Kliman, L. T.; Morken, J. P. J. Am. Chem. Soc. 2009, 131, 9134–9135.

Ph •

Pd2(dba)3 (2.5 mol %)(R,R)-L1 (6 mol %)B2(pin)2, toluene

OP

ON

O

O

ArAr

Ar ArL1: Ar = PhL2: Ar = 3,5-Me2C6H3

Ph

B(pin)B(pin)

88% ee

PhCHO, rtthen H2O2

PhO

Ph

OH

BO

O

O

Ph

B(pin)

Ph H

(pin)B

Ph

O

O

OB

PhH

A(1,2)56%, 82% ee

vs

Pd2(dba)3 (2.5 mol %)(R,R)-L1 (6 mol %)B2(pin)2, toluene

84% ee

then H2O2

66%, 82% eeMe5

5

MeB(pin)

PhCHO

5

MeOHB(pin)

PhHO

▪α-Chiral β-boryl allylboronates

▪α-Chiral σ-boryl allylboronates

Allylation with α,α-Disubstituted Allylboronates▪Previous works

B(pin)

Me CyPh

OHCy

RCHO

94% ee, 1:1 E/Zα-dialkyl

Ph

OH

94% ee, 10:1 E/Z

B(pin)RCHO

α-alkyl, β-methyl

B(pin)OMe

Ph

PhMe

H

Me

Favor TS (2.3 kcal/mol)

O

B(pin)Me

HPh

Me

Me

Disfavor TS rCH-Ar 3.4 Å

▶ Difficult to control E/Z selectivity

Guzman-Martinez, A.; Hoveyda, A. H. J. Am. Chem. Soc. 2010, 132, 10634–10637.Chen, J.; Scott, H. K.; Hesse, M. J.; Willis, C. L.; Aggarwal, V. J. Am. Chem. Soc. 2013.

Hesse, M. J.; Essafi, S.; Watson, C. G.; Harvey, J. N.; Hirst, D.; Willis, C. L.; Aggarwal, V. K. Angew. Chem. Int. Ed. 2014, 53, 1–6.

JACS, 2010 JACS, 2013

▪Enantio- and diastereoselective addition to aldehyde i) s-BuLi, Et2O –78 ºC, 15 minii)

B(pin)

RCHO, THF–78 ºC to rt, 16 h R

OH

99%, >99:1 dr, >99:1 er99%, >99:1 dr, 99:1 er

Ph

OCb

B(pin)

–78 ºC, 1 h

iii) reflux, 16 h

PhPh

R = PhR = Cy

Hydroboration-Aldehyde Allylboration Sequence

Brown, H. C.; Narla, G. J. Org. Chem. 1995, 60, 4686–4687.Barrett, A. G. M.; Braddock, D. C.; Koning, P. D.; White, A. J. P.; Williams, D. J. J. Org. Chem. 1999, 65, 375–380.

Flamme, E. M.; Roush, W. R. J. Am. Chem. Soc. 2002, 124, 13644–13645.Peng, F.; Hall, D. G. J. Am. Chem. Soc. 2007, 129, 3070–3071.

Chen, M.; Handa, M.; Roush, W. R. J. Am. Chem. Soc. 2009, 131, 14602–14603.Chen, M.; Ess, D. H.; Roush, W. R. J. Am. Chem. Soc. 2010, 132, 7881–7883.

Chen, M.; Roush, W. R. J. Am. Chem. Soc. 2011, 133, 5744–5747.Chen, M.; Roush, W. R. J. Am. Chem. Soc. 2013, 135, 9512–9517.

•R'2B

R1 R2

OH OH

R1

R2OH

OH

OB

O

OB O

PhPh

PhPh

65–87% 89–96% ee >20:1 dr

72–95% 91–95% ee >14:1 dr

-B(OR)2 =

R1CHO

R2CHOor

(dIpc)2BH

i) R1CHO ii) H2O2, NaOH

60–75% 90–95% ee >20:1 dr

R1

OH

OH

BR'2B

▪Allene hydroboration/aldehyde allylboration reaction sequences

γ-Alkoxyallylboronates

Hoffmann, R. W.; Kempher, B. Tetrahedron Lett. 1981, 22, 5263–5266.Wuts, P. G.; Bigelow, S. S. J. Org. Chem. 1982, 47, 2498–2500.

Brown, H. C.; Jadhav, P. K.; Bhat, K. S. J. Am. Chem. Soc. 1988, 110, 1535–1538.Moriya, T.; Suzuki, A.; Miyaura, N. Tetrahedron Lett. 1995, 36.

Ganesh, P.; Nicholas, K. M. J. Org. Chem. 1997, 62, 1737–1747.Yamamoto, Y.; Miyairi, T.; Ohmura, T.; Miyaura, N. J. Org. Chem. 1998, 64, 296–298.

Yamamoto, Y.; Kurihara, K.; Yamada, A.; Takahashi, M. Tetrahedron 2003, 59.Muñoz-Hernández, L.; Soderquist, J. A. Org. Lett. 2009, 11, 2571–2574.

B

MeO

Brown et al. (1988)

BTBSO O

OCO2

iPr

CO2iPr

Miyaura et al. (1998)

BTMS

OMe

Soderquist et al. (2009)

BMeO O

O

Hoffmann et al. (1981)Wuts et al. (1982)

O

B(pin)

R

Hall et al. (Cr and Pd cat.)R = OEt (2003), H (2009)

BnO

B(pin)

RMeO

B(pin)

Ito et al. (2014) (Cu cat.)

Deligny, M.; Carreaux, F.; Carboni, B.; Toupet, L. Chem. Commun. 2003, 276–277.Gao, X.; Hall, D. G. J. Am. Chem. Soc. 2003, 125, 9308–9309.

Possémé, F.; Deligny, M.; Carreaux, F.; Carboni, B. J. Org. Chem. 2007, 72, 984–989.Lessard, S.; Peng, F.; Hall, D. G. J. Am. Chem. Soc. 2009, 131, 9612–9613.

Penner, M.; Rauniyar, V.; Kaspar, L. T.; Hall, D. G. J. Am. Chem. Soc. 2009, 131, 14216–14217.Ding, J.; Hall, D. G. Angew. Chem. Int. Ed. 2013, 52, 1–6.

Yamamoto, E.; Ozaki, T.; Miya, T.; Ito, H. J. Am. Chem. Soc. 2014, 136, 16515–16521.

Allylation with α-Chiral γ-Alkoxyallylboronates

▪Asymmetric syntheses of heterocyclic γ-alkoxyallylboronates

▪Asymmetric synthesis of linear γ-alkoxyallylboronates

R'

ORRO R' OR

B(pin)CuCl/(R,R)-BenzP* R''CHO

R'

ORR''

OHZnBr2

68–82% yield, E/Z = 85:15–98:2anti/syn >95:5, 94–98% ee

62–94%, 91–98% ee

(pin)B–B(pin)K(O-t-Bu)

O B(pin)R

N

OCr

Oada

Cl

cat., MS 4 Å

O

B(pin)

R

PhCHO OPh

HOH

R

cat.O OTf

Pd(OAc)2TANIAPHOSBase R = OEt: >98% de, 96% ee

R = H: >96% de, 93% ee

Addition of Allylic Boronates to Carbonyl Derivatives...

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