Abstract
Optically pure tert -butanesulfinyl aldimines 1 were prepared by direct condensation of chiral tert -butanesulfinamide 3 with aldehydes 2 in high yields in the presence of KHSO4 . The main advantage of KHSO4 is that it is applicable to the condensation reactions of a variety of aldehydes, including electron deficient and electron rich (hetereo)aromatic aldehydes, as well as aliphatic aldehydes.
Key words
tert -butanesulfinamide - aldehyde -
tert -butanesulfinyl aldimines - potassium hydrogen sulfate - condensation
References
1a
Ellman JA.
Owens TD.
Tang TP.
Acc. Chem. Res.
2002,
35:
984
1b
Prakash GKS.
Mandal M.
J. Am. Chem. Soc.
2002,
124:
6538
1c
Kells KW.
Chong JM.
Org. Lett.
2003,
5:
4215
1d
Evans JW.
Ellman JA.
J. Org. Chem.
2003,
68:
9948
1e
Jacobsen MF.
Skrydstrup T.
J. Org. Chem.
2003,
68:
7112
1f
Davis FA.
Wu Y.-Zh.
Yan H.-X.
McCoull W.
Prasad KR.
J. Org. Chem.
2003,
68:
2410
1g
Zhong Y.-W.
Izumi K.
Xu M.-H.
Lin G.-Q.
Org. Lett.
2004,
6:
4747
1h
Schenkel LB.
Ellman JA.
Org. Lett.
2004,
6:
3621
1i
Zhong Y.-W.
Xu M.-H.
Lin G.-Q.
Org. Lett.
2004,
6:
3953
1j
Weix DJ.
Shi Y.
Ellman JA.
J. Am. Chem. Soc.
2005,
127:
1092
For the preparation of optically pure tert -butanesulfinamide see:
2a
Han Zh.-X.
Krishnamurthy D.
Grover P.
Fang QK.
Senanayake ChH.
J. Am. Chem. Soc.
2002,
124:
7880
2b
Weix DJ.
Ellman JA.
Org. Lett.
2003,
5:
1317
2c
Qin Y.
Wang C.-H.
Huang Zh.-Y.
Xiao X.
Jiang Y.-Zh.
J. Org. Chem.
2004,
69:
8533
3
Branchaud BP.
J. Org. Chem.
1983,
48:
3531
4a
Liu G.-Ch.
Cogan DA.
Owens TD.
Tang TP.
Ellman JA.
J. Org. Chem.
1999,
64:
1278
4b
Davis FA.
Zhang Y.
Andemichael Y.
Fang T.
Fanelli DL.
Zhang H.
J. Org. Chem.
1999,
64:
1403
5
Higashibayashi S.
Tohmiya H.
Mori T.
Hashimoto K.
Nakata M.
Synlett
2004,
457
6
Jiang Zh.-Y.
Chan WH.
Lee AWM.
J. Org. Chem.
2005,
70:
1081
7
Ke B.-W.
Qin Y.
He Q.-F.
Huang Zh.-Y.
Wang F.-P.
Tetrahedron Lett.
2005,
46:
1751
8 General procedure: (S )-tert -Butanesulfinamide (1 mmol) was stirred with benzaldehyde (2 mmol) in toluene (10 mL) in the presence of KHSO4 (2 equiv) for 24 h at 45 °C. KHSO4 was then removed by filtration. The filtrate was concentrated to dryness. The residue was purified by flash chromato-graphy to afford (S )-tert -butanesulfinyl aldimine (1a ) as a colorless liquid. [α]D
20 +105 (c 2.19, CHCl3 , Lit.
[5 ]
[10 ]
[α]D
20 +104, CHCl3 ). 1 H NMR and 13 C NMR spectra were identical to that reported in the literature.
[5 ]
[10 ]
The ee of synthesized aldimine 1 , determined by HPLC analysis (Daicel Chiralcel OD column), was over 99%.
[4 ]
[5 ]
9
Davis FA.
Reddy RE.
Szewczyk JM.
Reddy GV.
Portonovo PS.
Zhang H.
Fanelli D.
Reddy RT.
Zhou P.
Carroll PJ.
J. Org. Chem.
1997,
62:
2555
10
Ruano JLG.
Fernandez I.
del Catalina MP.
Cruz AA.
Tetrahedron: Asymmetry
1996,
7:
3407