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(a) Llera, J. M.; Fernández, I.; Alcudia, F. Tetrahedron Lett. 1991, 32, 7299–7302;
b) Fernández, I.; Khiar, N.; Llera, J. M.; Alcudia, F. J. Org. Chem. 1992, 57, 6789–
References and notes
(
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796; (c) Khiar, N.; Fernández, I.; Alcudia, F. Tetrahedron Lett. 1994, 35, 5719–
722; (d) Khiar, N.; Alcudia, F.; Espartero, J.-L.; Rodríguez, L.; Fernández, I. J. Am.
1
.
(a) Liu, G.; Cogan, D. A.; Ellman, J. A. J. Am. Chem. Soc. 1997, 119, 9913–9914; (b)
Davis, F. A.; Reddy, R. T.; Reddy, R. E. J. Org. Chem. 1992, 57, 6387–6389; (c)
Weix, D. J.; Ellman, J. A. Org. Synth. 2005, 82, 157–162.
Chem. Soc. 2000, 122, 7598–7599; (e) Khiar, N.; Araujo, C.; Alcudia, F.;
Fernández, I. J. Org. Chem. 2002, 67, 345–356; (f) Ballcells, D.; Maseras, F.;
Khiar, N. Org. Lett. 2004, 6, 2197–2200; (g) Balcells, D.; Ujaque, G.; Fernández, I.;
Khiar, N. Adv. Synth. Catal. 2007, 349, 2103–2110.
0. Drabowicz et al. have previously studied the reaction of t-BuSOCl with alcohols
and found that NEt and 8 in Et O gave a dr of 91:9 and 66% yield after 3 days.
2
.
For reviews see: (a) Ellman, J. A.; Owens, T. D.; Tang, T. P. Acc. Chem. Res. 2002,
35, 984–995; (b) Ellman, J. A. Pure Appl. Chem. 2003, 75, 39–46; (c) Zhou, P.;
Chen, B.-C.; Davis, F. A. Tetrahedron 2004, 60, 8003–8030; (d) Daniel, M.;
Stockman, R. A. Tetrahedron 2006, 62, 8868–8905; (e) Lin, G.-Q.; Xu, M.-H.;
Zhong, Y.-W.; Sun, X.-W. Acc. Chem. Res. 2008, 41, 831–840.
1
1
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2
They attributed the low yield to trapping of 8 as its HCl salt but noted that
added base had a limited effect on yield and dr. They also noted that there was
little effect of solvent on diastereocontrol: Drabowicz, J.; Bujnicki, B.; Biscarini,
P.; Mikolajczyk, M. Tetrahedron: Asymmetry 1999, 10, 3177–3187.
3
.
.
Unthank, M. G.; Hussain, N.; Aggarwal, V. K. Angew. Chem., Int. Ed. 2006, 45,
7
066–7069. Angew. Chem. 2006, 118, 7224–7227.
(a) Wuts, P. G. M.; Greene, T. W. Greene’s Protective Groups in Organic Synthesis,
th ed.; John Wiley & Sons: Hoboken, 2007; (b) Sun, P.; Weinreb, S. M. J. Org.
4
4
1. For other dynamic kinetic resolution approaches see: (a) Evans, J. W.; Fierman,
M. B.; Miller, S. J.; Ellman, J. A. J. Am. Chem. Soc. 2004, 126, 8134–8135; (b)
Peltier, H. M.; Evans, J. W.; Ellman, J. A. Org. Lett. 2005, 7, 1733–1736; (c)
Shibata, N.; Matunaga, M.; Nakagawa, M.; Fukuzumi, T.; Nakamura, S.; Toru, T.
J. Am. Chem. Soc. 2005, 127, 1374–1375; (d) Shibata, N.; Matsunaga, M.;
Fukuzumi, T.; Nakamura, S.; Toru, T. Synlett 2005, 1699–1702.
2. Kice, J. L.; Lee, T. W. S.; Pan, S.-T. J. Am. Chem. Soc. 1980, 102, 4448–4455.
3. For capture of the p-toluenesulfinyl auxiliary with menthol followed by cycles
of fractional crystallization and epimerization see: Davis, F. A.; Reddy, R. E.;
Szewczyk, J. M. J. Org. Chem. 1995, 60, 7037–7039.
4. (a) Han, Z.; Krishnamurthy, D.; Grover, P.; Fang, Q. K.; Su, X.; Wilkinson, H. S.;
Lu, Z.-H.; Magiera, D.; Senanayake, C. H. Tetrahedron 2005, 61, 6386–6408; (b)
Han, Z.; Krishnamurthy, D.; Grover, P.; Fang, Q. K.; Senanayake, C. H. J. Am.
Chem. Soc. 2002, 124, 7880–7881; (c) Han, Z.; Krishnamurthy, D.; Pflum, D.;
Grover, P.; Wald, S. A.; Senanayake, C. H. Org. Lett. 2002, 4, 4025–4028.
5. The standard work-up uses MeOH/HCl which presumably traps the sulfinyl
chloride as methyl tert-butylsulfinate ester.
Chem. 1997, 62, 8604–8608.
5
.
.
(a) Greenwood, N. N.; Earnshaw, A. Chemistry of the Elements; Pergammon Press
plc: Oxford, 1984; pp 821–824; (b) Grainger, R. S.; Procopio, A.; Steed, J. W. Org.
Lett. 2001, 3, 3565–3568.
6
Ellman reported the production of tert-butanesulfinic acid on treatment of a
sulfinamide with TFA-d
Brinner, K. M.; Ellman, J. A. Org. Biomol. Chem. 2005, 3, 2109–2113; Ellman used
NH Cl as an additive for auxiliary cleavage by acidic resins and MeOH, and
1 2
/D O in an NMR study but it was not isolated: (a)
1
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suggested it was effective due to attack of chloride at sulfur: (b) Mukade, T.;
Dragoli, D. R.; Ellman, J. A. J. Comb. Chem. 2003, 5, 590–596.
For leading references see: (a) Solladié, G.; Hutt, J.; Girardin, A. Synthesis 1987,
1
7
.
.
1
73; (b) Solladié, G. Synthesis 1981, 185–196.
Milder conditions (dilute HCl, or use of NH Cl) either caused racemization or no
reaction. Use of an acid with a non-nucleophilic counterion (e.g., HBF ) with
MeOH or menthol gave racemization or no deprotection. Activation of the
sulfinamide with a Boc group (successful) followed by treatment with NH or
LiNH returned starting material.
8
4
4
1
3
2