References and Notes
-
1a
Arduengo AJ.
Herlow RL.
Kline M.
J. Am. Chem. Soc.
1991,
117:
361
-
1b Review: Arduengo AJ.
Krafczyk R.
Chem. Unserer Zeit
1998,
32:
6
-
1c
Enders D.
Breuer K.
Raabe G.
Runsink J.
Teles JH.
Melder J.-P.
Ebel K.
Brode S.
Angew. Chem. Int. Ed.
1995,
34:
2021
-
1d Review: Canac Y.
Soleilhavoup M.
Conejero S.
Bertrand G.
J. Organomet. Chem.
2004,
689:
3857
-
Reviews:
-
2a
Enders D.
Balensiefer T.
Acc. Chem. Res.
2004,
37:
534
-
2b
Zeitler K.
Angew. Chem. Int. Ed.
2005,
44:
7506
-
2c
Enders D.
Balensiefer T.
Niemeier O.
Christmann M.
Nucleophilic N-Heterocyclic Carbenes in Asymmetric Synthesis In Enantioselective Organocatalysis - Reactions and Experimental Procedures
Dalko P.
Wiley-VCH;
Weinheim:
2006. in press
-
3a
Burstein C.
Glorius F.
Angew. Chem. Int. Ed.
2004,
43:
6205
-
3b
Sohn SS.
Rosen EL.
Bode JW.
J. Am. Chem. Soc.
2004,
126:
14370
-
3c
He M.
Bode JW.
Org. Lett.
2005,
7:
3131
-
3d
Mattson AE.
Zuhl AM.
Reynolds TE.
Scheidt KA.
J. Am. Chem. Soc.
2006,
128:
4932
- 4
Singh R.
Kissling RM.
Letellier M.-A.
Nolan SP.
J. Org. Chem.
2004,
69:
209
- 5
Coulembier O.
Dove AP.
Pratt RC.
Sentman AC.
Culkin DA.
Mespouille L.
Dubois P.
Waymouth RM.
Hedrick JL.
Angew. Chem. Int. Ed.
2005,
44:
4964
- 6
Fischer C.
Smith SW.
Powell DA.
Fu GC.
J. Am. Chem. Soc.
2006,
128:
1472
- 7
Chan A.
Scheidt KA.
J. Am. Chem. Soc.
2006,
128:
4558
- 8
Song JJ.
Tan Z.
Reeves JT.
Gallou F.
Yee NK.
Senanayake CH.
Org. Lett.
2005,
7:
2193
-
9a
Mattson AE.
Bharadwaj AR.
Scheidt KA.
J. Am. Chem. Soc.
2004,
126:
2314
-
9b
Bharadwaj AR.
Scheidt KA.
Org. Lett.
2004,
6:
2465
-
9c
Mattson AE.
Scheidt KA.
Org. Lett.
2004,
6:
4363
- 10
Enders D.
Kallfass U.
Angew. Chem. Int. Ed.
2002,
41:
1743
-
11a
Enders D.
Breuer K.
Runsink J.
Teles JH.
Helv. Chim. Acta
1996,
79:
1899
-
11b
Kerr MS.
de Alaniz JR.
Rovis T.
J. Am. Chem. Soc.
2002,
35:
10298
-
11c
Kerr MS.
Rovis T.
J. Am. Chem. Soc.
2004,
126:
8876
-
11d
de Alaniz JR.
Rovis T.
J. Am. Chem. Soc.
2005,
127:
6284
-
11e
Liu Q.
Rovis T.
J. Am. Chem. Soc.
2006,
128:
2552
-
11f Short review: Christmann M.
Angew. Chem. Int. Ed.
2005,
44:
2632
-
12a
Mennen SM.
Gipson JD.
Kim YR.
Miller SJ.
J. Am. Chem. Soc.
2005,
127:
1654
-
12b
Murry JA.
Frantz DE.
Soheili A.
Tillyer R.
Grabowski EJJ.
Reider PJ.
J. Am. Chem. Soc.
2001,
123:
9696
-
13a
Linghu X.
Johnson JS.
Angew. Chem. Int. Ed.
2003,
42:
2534
-
13b
Linghu X.
Potnick JR.
Johnson JS.
J. Am. Chem. Soc.
2004,
126:
3070
-
13c
Linghu X.
Bausch CC.
Johnson JS.
J. Am. Chem. Soc.
2005,
127:
1833
-
Enzymatic cross-coupling:
-
14a
Iding H.
Dünnwald T.
Greiner L.
Liese A.
Müller M.
Siegert P.
Grötzinger J.
Demir AS.
Pohl M.
Chem. Eur. J.
2000,
6:
1483
-
14b
Dünkelmann P.
Kolter-Jung D.
Nitsche A.
Demir AS.
Siegert P.
Lingen B.
Baumann M.
Pohl M.
Müller M.
J. Am. Chem. Soc.
2002,
124:
12084
-
14c
Pohl M.
Lingen B.
Müller M.
Chem. Eur. J.
2002,
8:
5289
-
15a
Hachisu Y.
Bode JW.
Suzuki K.
J. Am. Chem. Soc.
2003,
125:
8432
-
15b
Enders D.
Niemeier O.
Synlett
2004,
2111
-
15c
Hachisu Y.
Bode JW.
Suzuki K.
Adv. Synth. Catal.
2004,
346:
1097
-
16a
Enders D.
Niemeier O.
Balensiefer T.
Angew. Chem. Int. Ed.
2006,
45:
1463
-
16b For a related study, see: Takikawa H.
Hachisu Y.
Bode JW.
Suzuki K.
Angew. Chem. Int. Ed.
2006,
45:
3492
-
Reviews:
-
17a
Fuji K.
Chem. Rev.
1993,
93:
2037
-
17b
Corey EJ.
Guzman-Perez A.
Angew. Chem. Int. Ed.
1998,
37:
388
-
17c
Christoffers J.
Mann A.
Angew. Chem. Int. Ed.
2001,
40:
4591
-
17d
Denissova I.
Barriault L.
Tetrahedron
2003,
59:
10105
-
18a
Heller W.
Tamm C.
Fortschr. Chem. Org. Naturst.
1981,
40:
105
-
18b
Davies FA.
Weismiller MC.
J. Org. Chem.
1990,
55:
3715
-
19a
Böhler P.
Tamm C.
Tetrahedron Lett.
1967,
36:
3479
-
19b
Crouch NR.
Bangnai V.
Mulholland DA.
Phytochemistry
1999,
51:
943
20 Aldehyde ketones of type 5 can be synthezised by the reaction of the corresponding salicyl aldehydes, K2CO3 and α-bromo ketones in DMF at r.t.
21 CCDC 607797 (6a) and CCDC 607796 (6f) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
22 All new compounds were fully characterized (IR, NMR, MS, elemental analysis, optical rotation, and melting point).
Enantioselective Intramolecular Crossed-Chromanone Cyclization to 6a; Typical Procedure
In a Schlenk tube under argon at r.t. the pre-catalyst 1 (39.0 mg, 0.104 mmol, 20 mol%) was suspended in anhyd THF (9.5 mL). KHMDS (0.5 M in toluene; 198 µL, 0.099 mmol, 19 mol%) was added slowly, and the solution stirred for 15 min. The yellow solution was cooled to 5 °C and the aldehyde ketone 5a (100 mg, 0.520 mmol) dissolved in anhyd THF (1.0 mL) was added to the carbene solution. The reaction mixture was stirred for 48 h, diluted with CH2Cl2, quenched with H2O, extracted twice with CH2Cl2, and dried over MgSO4. The solvent was evaporated and the crude product was purified by flash chromatography on silica gel (Et2O-n-pentane, 1:8) to yield 6a (88 mg, 88%) as a colorless solid; mp 48 °C; ee 94% [determined by chiral stationary phase GC (Lipodex E)]; [α]D
23 -10.3 (c 1.2, CHCl3). IR (KBr): 3853, 3742, 3482, 2973, 2361, 2340, 1837, 1690, 1610, 1558, 1465, 1382, 1311, 1215, 1134, 1021, 942, 862, 758, 670, 533. 1H NMR (300 MHz, CDCl3, TMS): δ = 0.95 (t, 3 H, J = 7.4 Hz, CH3), 1.81 (q, 2 H, J = 7.5 Hz, CH3CH2), 3.68 (s, 1 H, OH), 4.17 (d, 1 H, J = 11.4 Hz, CHH), 4.40 (d, 1 H, J = 11.4 Hz, CHH), 6.96-7.08 (m, 2 H, Ar), 7.48-7.54 (m, 1 H, Ar), 7.86-7.89 (m, 1 H, Ar). 13C NMR (75 MHz, CDCl3): δ = 6.8 (CH3), 27.6, 72.8 (CH2), 73.0 (C), 117.9 (CH), 118.4 (C), 127.5, 136.5 (CH), 161.4 (C), 196.8 (CO). MS (EI): m/z (%) = 192 (M+, 11), 122 (7), 121 [(M+ + 1) - 72, 100], 120 (11), 93 (7), 92 (18), 77 (5), 65 (6). Anal. Calcd for C11H12O3: C, 68.75; H, 6.29. Found: C, 68.69; H, 6.28.