High-Pressure Enantioselective Allylation of Aldehydes Catalyzed by (Salen)Chromium(III) Complexes

Abstract

The enantioselective addition of allyltributyltin to simple aldehydes (2a-l), catalyzed by chiral (salen)Cr(III) complexes 1, has been studied. The reaction proceeds smoothly with low loading (1-2 mol%) of (salen)Cr(III)BF₄ (1a) and allyltributyltin under high-pressure conditions (10 kbar) in good yield and ee values in the range of 35-79%.

aldehydes - allylstannane - asymmetric catalysis - high-pressure technique - homoallylic alcohols - salen-chromium complexes

References

<A NAME="RG34904ST-1">1</A> For a recent review, see: Denmark SE. Fu J. Chem. Rev.  2003,  103:  2763 

<A NAME="RG34904ST-2">2</A> Gung BW. In Organic Reactions   Vol. 64:  J. Wiley and Sons; New York: 2004.  Chap. 1.

<A NAME="RG34904ST-3A">3a</A> Costa AL. Piazza MG. Tagliavini E. Trombini C. Umani-Ronchi A. J. Am. Chem. Soc.  1993,  115:  7001 

<A NAME="RG34904ST-3B">3b</A> Keck GE. Tarbet KH. Geraci LS. J. Am. Chem. Soc.  1993,  115:  8467 

<A NAME="RG34904ST-3C">3c</A> Aoki S. Mikami K. Terada M. Nakai T. Tetrahedron  1993,  49:  1783 

<A NAME="RG34904ST-4A">4a</A> Bedeschi P. Casolari S. Costa AL. Tagliavini E. Umani-Ronchi A. Tetrahedron Lett.  1995,  36:  7897 

<A NAME="RG34904ST-4B">4b</A> Casolari S. Cozzi PG. Orioli PA. Tagliavini E. Umani-Ronchi A. Chem.Commun.  1997,  2123 

<A NAME="RG34904ST-4C">4c</A> Hanawa H. Kii S. Asao N. Maruoka K. Tetrahedron Lett.  2000,  41:  5543 

<A NAME="RG34904ST-4D">4d</A> Kurosu M. Lorca M. Tetrahedron Lett.  2002,  43:  1765 

<A NAME="RG34904ST-5">5</A> Furuta K. Mouri M. Yamamoto H. Synlett  1991,  561 

<A NAME="RG34904ST-6">6</A> Yanagisawa A. Nakashima H. Ishiba A. Yamamoto H. J. Am. Chem. Soc.  1996,  118:  4723 

<A NAME="RG34904ST-7">7</A> Motoyama Y. Narusawa H. Nishiyama H. Chem. Commun.  1999,  131 

<A NAME="RG34904ST-8">8</A> Bandini M. Cozzi PG. Melchiorre P. Umani-Ronchi A. Angew. Chem. Int. Ed.  1999,  38:  3357 

<A NAME="RG34904ST-9A">9a</A> Bandini M. Cozzi PG. Umani-Ronchi A. Angew. Chem. Int. Ed.  2000,  39:  2327 

<A NAME="RG34904ST-9B">9b</A> Bandini M. Cozzi PG. Umani-Ronchi A. Tetrahedron  2001,  57:  835 

<A NAME="RG34904ST-9C">9c</A> Bandini M. Cozzi PG. Melchiorre P. Morganti S. Umani-Ronchi A. Org. Lett.  2001,  3:  1153 

<A NAME="RG34904ST-9D">9d</A> Berkessel A. Menche D. Sklorz CA. Schröder M. Paterson I. Angew. Chem. Int. Ed.  2003,  42:  1032 

<A NAME="RG34904ST-9E">9e</A> Lombardo M. Licciulli S. Morganti S. Trombini C. Chem. Commun.  2003,  1762 

<A NAME="RG34904ST-9F">9f</A> Bandini M. Cozzi PG. Licciulli S. Umani-Ronchi A. Synthesis  2004,  409 

<A NAME="RG34904ST-10">10</A> Kwiatkowski P. Chaladaj W. Jurczak J. Tetrahedron Lett.  2004,  45:  5343 

<A NAME="RG34904ST-11A">11a</A> Martínez LE. Leighton JL. Carsten DH. Jacobsen EN. J. Am. Chem. Soc.  1995,  117:  5897 

<A NAME="RG34904ST-11B">11b</A> Leighton JL. Jacobsen EN. J. Org. Chem.  1996,  61:  389 

<A NAME="RG34904ST-12">12</A> Schaus SE. Brånalt J. Jacobsen EN. J. Org. Chem.  1998,  63:  403 

For a review of applications of the(salen)Cr complexes in asymmetric catalysis, see:

<A NAME="RG34904ST-13A">13a</A> Bandini M. Cozzi PG. Umani-Ronchi A. Chem. Commun.  2002,  919 

<A NAME="RG34904ST-13B">13b</A> Larrow JF. Jacobsen EN. Top. Organomet. Chem.  2004,  6:  123 

<A NAME="RG34904ST-14A">14a</A> Kwiatkowski P. Asztemborska M. Caille J.-C. Jurczak J. Adv. Synth. Catal.  2003,  506 

<A NAME="RG34904ST-14B">14b</A> Kwiatkowski P. Asztemborska M. Jurczak J. Synlett  2004,  1755 

<A NAME="RG34904ST-14C">14c</A> Kwiatkowski P. Asztemborska M. Jurczak J. Tetrahedron: Asymmetry  2004,  15:  3189 

<A NAME="RG34904ST-15">15</A> Malinowska M. Kwiatkowski P. Jurczak J. Tetrahedron Lett.  2004,  45:  7693 

<A NAME="RG34904ST-16A">16a</A> High Pressure Chemical Synthesis   Jurczak J. Baranowski B. Elsevier; New York: 1989. 

<A NAME="RG34904ST-16B">16b</A> Organic Synthesis at High Pressure   Matsumato K. Acheson RM. Wiley; New York: 1991. 

<A NAME="RG34904ST-16C">16c</A> Chemistry under Extreme or Non-Classical Conditions   van Eldik R. Hubbard CD. Wiley; New York: 1997. 

<A NAME="RG34904ST-17A">17a</A> Yamamoto Y. Maruyama K. Matsumoto K. J. Chem. Soc., Chem. Commun.  1983,  489 

<A NAME="RG34904ST-17B">17b</A> Yamamoto Y. Yatagai H. Ishihara Y. Maeda N. Maruyama K. Tetrahedron  1984,  40:  2239 

<A NAME="RG34904ST-17C">17c</A> Yamamoto Y. Komatsu T. Maruyama K. J. Organomet. Chem.  1985,  285:  31 

<A NAME="RG34904ST-17D">17d</A> Yamamoto Y. Saito K.-i. J. Chem. Soc., Chem. Commun.  1989,  1676 

<A NAME="RG34904ST-18">18</A> Cokley TM. Isaacs NS. McCluskey A. Young DJ. Main Group Met. Chem.  1997,  20:  581 

<A NAME="RG34904ST-19">19</A> Halligan NG. Blaszczak LC. Org. Synth.  1990,  68:  104 

<A NAME="RG34904ST-20">20</A>

General Procedure for the High-Pressure Allylation:
In a 2 mL Teflon ampoule were placed (salen)CrBF₄ (2a, usually 13.7mg, 2 mol%), ca. 1 mL of solvent (usually CH₂Cl₂), followed by aldehyde (usually 1 mmol) and allyltributyltin (1.1 equiv). Finally, the ampoule was made up with solvent, closed and placed in a high-pressure vessel, and pressure was slowly increased to 10 kbar at 20 °C. After stabilization of pressure, the reaction mixture was kept under these conditions for 24 h. After decompression, the reaction mixture was diluted with wet Et₂O, and dried over MgSO₄. After evaporation of solvents, the residue was chromatographed on a silica gel column using hexane-EtOAc. All liquid aldehydes were distilled prior to use.

<A NAME="RG34904ST-21">21</A>

Enantioselectivity of homoallylic alcohols 3a-l was determined by GC employing a capillary chiral β-dex 120 column. Alcohols 3c,k were analyzed directly, 3a,b,d-h,j as their O-trimethylsilyl derivatives, 3i as a trifluoroacetate and 3l as a isopropylidene derivative of pent-4-ene-1,2-diol.