References and Notes
- 1
Xu LW.
Luo J.
Lu X.
Chem.
Commun.
2009,
1807
- 2
Mukherjee S.
Yang JW.
Hoffmann S.
List B.
Chem. Rev.
2007,
107:
5471
- 3 For either diastereoselective or
organocatalytic electrophilic α-amination, see: Greck C.
Drouillat B.
Thomassigny C.
Eur. J. Org. Chem.
2004,
1377
- 4
Bogevig A.
Juhl K.
Kumaragurubaran N.
Zhuang W.
Jørgensen KA.
Angew. Chem. Int. Ed.
2002,
41:
1790
- 5
List B.
J.
Am. Chem. Soc.
2002,
124:
5656
-
6a
Vogt H.
Vanderheiden S.
Bräse S.
Chem. Commun.
2003,
2448
-
6b
Baumann T.
Vogt H.
Bräse S.
Eur.
J. Org. Chem.
2007,
266
-
6c
Baumann T.
Bächle M.
Hartmann C.
Bräse S.
Eur. J. Org. Chem.
2008,
2207
-
7a
Kumaragurubaran N.
Juhl K.
Zhuang W.
Bogevig A.
Jørgensen KA.
J. Am.
Chem. Soc.
2002,
124:
6254
-
7b
Liu T.
Cui H.
Zhang Y.
Jiang K.
Du W.
He Z.
Chen Y.
Org. Lett.
2007,
9:
3671
-
8a
Dahlin N.
Bøgevig A.
Adolfsson H.
Adv. Synth. Catal.
2004,
346:
1101
-
8b
Thomassigny C.
Prim D.
Greck C.
Tetrahedron
Lett.
2006,
47:
1117
-
8c
Hayashi Y.
Arakate S.
Imai Y.
Hibino K.
Chen QY.
Yamaguchi J.
Uchimaru T.
Chem. Asian.
J.
2008,
3:
225
-
9a
de Figueiredo RM.
Christmann M.
Eur. J. Org. Chem.
2007,
2575 ; and references cited therein
-
9b
Sudalai A.
Tetrahedron
2007,
63:
9758
-
9c
George S.
Suryavanshi GS.
Sudalai A.
Tetrahedron
Lett.
2008,
49:
6791
-
9d
Kalch D.
De Rycke N.
Moreau X.
Greck C.
Tetrahedron Lett.
2009,
50:
492
-
9e
Nishikawa Y.
Kitajima M.
Kogure N.
Takayama H.
Tetrahedron
2009,
65:
1608
- 11 To determine the relative configuration
of anti-2, we synthesized
this compound via diastereoselective electro-philic amination method
from ethyl (R)-3-hydroxybutyrate using
LDA, ZnBr2 and DBAD. For this reaction, see: Genêt JP.
Jugé S.
Mallart S.
Tetrahedron Lett.
1998,
29:
6765
- 13
Ait-Youcef R.
Kalch D.
Moreau X.
Thomassigny C.
Greck C.
Lett. Org.
Chem.
2009,
6:
377
- 14
Franzén J.
Marigo M.
Fielenbach D.
Kjrsgaard A.
Jørgensen KA.
J. Am. Chem. Soc.
2005,
127:
18296
- 16
Bourdreux Y.
Drouillat B.
Greck C.
Synlett
2005,
2086
- 17
Poupardin O.
Greck C.
Genêt JP.
Synlett
1998,
1279
10 3-tert-Butyldimethylsilyloxybutanal
(1) was synthesized in two steps (TBS protection
and DIBAL-H reduction of the ester moiety) from ethyl 3-hydroxybutyrate
commercially available in both enantiomeric forms.
12
General Procedure
for the Organocatalytic α-Amination: Dibenzylazodicarboxylate
(1 mmol) and d- or l-proline
(0.2 mmol, 20 mol%) in MeCN (10 mL) were treated with an
aldehyde (1.5 mmol) at r.t. The reaction mixture was stirred at
this temperature until the yellow color of the azodicarboxylate
had disappeared. The mixture was treated with EtOH (10 mL) and NaBH4 (40
mg) and was stirred for 5 min at 0 ˚C. The reaction was
worked up with aq NH4Cl solution and EtOAc. The organic
layers were dried (MgSO4), filtered, and concentrated.
Medium-pressure column chromatography on silica gel with EtOAc-pentane mixture
(1:4) gave the desired anti- or syn-2-hydrazino-1,3-diol as a single
diastereomer.
15
Characterization
of Selected Compounds:
Compound 2: ¹H
NMR (300 MHz, CDCl3): δ = 0.01-0.05 (m,
6 H), 0.86 (s, 9 H), 1.08-1.16 (m, 3 H), 3.51-3.99
(m, 4 H), 4.15-4.33 (m, 1 H), 5.16-5.29 (m, 4
H), 6.54 (s, 1 H), 7.28-7.37 (m, 10 H). ¹³C
NMR (75 MHz, CDCl3): δ = -5.1, -4.3,
17.7, 21.1, 25.6, 59.1, 59.6, 66.3, 67.0, 67.4, 68.1, 68.3, 68.5,
127.5, 127.7, 128.0, 128.1, 128.3, 128.4, 128.5, 135.0, 135.4, 135.6,
156.0, 157.0, 158.2, 158.9. MS (ESI): m/z = 525.4 [M + Na+].
IR: 3409, 3272, 2955, 2856, 1722, 1268, 1097, 833, 777, 696 cm-¹.
Anal. Calcd for C26H38N2O6Si:
C, 62.12; H, 7.62; N, 5.57. Found: C, 62.06; H, 7.55; N, 5.48. [α]D
²5 -25
(c = 1, CH2Cl2)
for (S,R)-2; [α]D
²5 +24
(c = 1, CH2Cl2)
for (R,S)-2.
Compound 3: ¹H
NMR (300 MHz, CDCl3): δ = (-0.01)-0.05 (m,
6 H), 0.81-0.82 (m, 9 H), 1.08-1.18 (m, 3 H),
3.48-4.04 (m, 4 H), 4.20-4.38 (m, 1 H), 5.14-5.30
(m, 4 H), 6.69-6.74 (m, 1 H), 7.32-7.37 (m, 10
H). ¹³C NMR (75 MHz, CDCl3): δ = -5.3, -5.2, -4.3, -4.2,
17.6, 21.2, 21.3, 25.5, 25.6, 59.7, 59.8, 64.1, 65.8, 68.1, 68.2,
68.5, 68.7, 127.6, 128.0, 128.1, 128.2, 128.4, 128.5, 135.2, 135.5,
135.8, 156.3, 156.9, 157.6, 158.2. MS (ESI): m/z = 525.4 [M + Na+].
IR: 3401, 3270, 2953, 2855, 1721, 1256, 1072, 836, 776, 696 cm-¹. Anal.
Calcd for C26H38N2O6Si:
C, 62.12; H, 7.62; N, 5.57. Found: C, 62.02; H, 7.35; N, 5.55. [α]D
²5 -3
(c = 1, CH2Cl2) for
(R,R)-3; [α]D
²5 +3
(c = 1, CH2Cl2)
for (S,S)-3.