The Reaction of α,β-Unsaturated Sulfones with Isobenzofuran and N-Boc-isoindole Using Warrener’s Methodology

Abstract

The cycloaddition reaction of vinyl and acetylenic sulfones with isobenzofuran {benzo[c]furan} and N-Boc-isoindole generated in situ using Warrener’s tetrazine method is described for the first time.

Diels-Alder reactions - sulfones - isobenzofuran - isoindole - Warrener’s reaction.

References and Notes

For reviews on the reaction, synthesis, and applications of benzofurans including isobenzofurans see:

<A NAME="RG41407ST-1A">1a</A> Hou XL. Yang Z. Wong HNC. Progress in Heterocyclic Chemistry   Part 3, Vol. 15:  Gribble GW. Joule JA. Pergamon; Oxford: 2003.  Chap. 5. p.192-199  

<A NAME="RG41407ST-1B">1b</A> Hou XL. Yang Z. Yeung KS. Wong HNC. Progress in Heterocyclic Chemistry   Part 3, Vol. 16:  Gribble GW. Joule JA. Pergamon; Oxford: 2004.  Chap. 5. p.180-188  

<A NAME="RG41407ST-1C">1c</A> Hou XL. Yang Z. Yeung KS. Wong HNC. Progress in Heterocyclic Chemistry   Part 3, Vol. 17:  Gribble GW. Joule JA. Pergamon; Oxford: 2005.  Chap. 5. p.158-164  

<A NAME="RG41407ST-1D">1d</A> Hou XL. Yang Z. Yeung KS. Wong HNC. Progress in Heterocyclic Chemistry   Part 3, Vol. 18:  Gribble GW. Joule JA. Pergamon; Oxford: 2006.  Chap. 5. p.203-210  

<A NAME="RG41407ST-1E">1e</A> Hou XL. Yang Z. Yeung KS. Wong HNC. Progress in Heterocyclic Chemistry   Part 3, Vol. 19:  Gribble GW. Joule JA. Pergamon; Oxford: 2007.  Chap. 5. p.193-200  ; see also previous issues of this series

<A NAME="RG41407ST-1F">1f</A> For a more extensive review on isobenzofuran, including many synthetic applications, see: Rodrigo R. Tetrahedron  1988,  44:  2093 

<A NAME="RG41407ST-1G">1g</A> For reviews on the isoindole chemistry, see: Bounett R. North SA. Adv. Heterocycl. Chem.  1981,  29:  341 

<A NAME="RG41407ST-1H">1h</A> See also: Joule JA. In Rodd’s Chemistry of Carbon Compounds   2nd ed.:  Elsevier; Amsterdam: 1997.  p.557-605  

For methods of generation of IBF excluding Warrener’s methodology, see ref. 1f and:

<A NAME="RG41407ST-2A">2a</A> Peters O. Friedrichsen W. Trends Heterocycl. Chem.  1995,  4:  217 

<A NAME="RG41407ST-2B">2b</A> Hurst DT. In Rodd’s Chemistry of Carbon Compounds   2nd ed.:  Elsevier; Amsterdam: 1997.  p.283-335  

<A NAME="RG41407ST-2C">2c</A> Friedrichsen W. Adv. Heterocycl. Chem.  1999,  73:  1 

For others more recent references, see:

<A NAME="RG41407ST-2D">2d</A> Sambaiah T. Huang DJ. Cheng CW. J. Chem. Soc., Perkin Trans. 1  2000,  195-203  

<A NAME="RG41407ST-2E">2e</A> Mikami K. Ohmura H. Org. Lett.  2002,  4:  3355 

<A NAME="RG41407ST-2F">2f</A>

See also ref. 10.

Isobenzofurans:

<A NAME="RG41407ST-3A">3a</A> Warrener RN. J. Am. Chem. Soc.  1971,  93:  2346 

<A NAME="RG41407ST-3B">3b</A> Russell RA. Longmore RW. Warrener RN. Weersuria KD. Aust. J. Chem.  1991,  44:  1341 

Isoindoles:

<A NAME="RG41407ST-3C">3c</A> Watson PL. Warrener RN. Tetrahedron Lett.  1972,  4295 

<A NAME="RG41407ST-3D">3d</A> Malpass JR. Sun G. Fawcett J. Warrener RL. Tetrahedron Lett.  1998,  39:  3083 

For the synthesis and isolation of mono- and bisoxadisilole fused isobenzofurans, see:

<A NAME="RG41407ST-3E">3e</A> Chen YL. Hau ChK. Wang H. He H. Wong MS. Lee AWM. J. Org. Chem.  2006,  71:  3512 

These reactions coupled with 1,3-dipolar cycloaddition reactions constitute the synthetic strategy for the stereocontrolled construction of [n]polynorbornanes structures. For reviews, see:

<A NAME="RG41407ST-4A">4a</A> Warrener RN. Butter ON. Russell RA. Synlett  1998,  566 

<A NAME="RG41407ST-4B">4b</A> Warrener RN. Eur. J. Org. Chem.  2000,  3363 

For theoretical calculations on these reactions, see:

<A NAME="RG41407ST-4C">4c</A> Dinadayaladane TC. Tandapani C. Sastry GN. J. Chem. Soc., Perkin Trans. 2  2002,  1902 

<A NAME="RG41407ST-4D">4d</A> Dinadayaladane TC. Punnagay M. Sastry GN. THEOCHEM  2003,  626:  247 

<A NAME="RG41407ST-4E">4e</A> Margetic D. Warrener RN. Dibbfe PW. J. Mol. Model.  2004,  10:  87 

<A NAME="RG41407ST-5">5</A> Simpkins NL. In Sulphones in Organic Synthesis   Baldwin JE. Magnus PD. Tetrahedron Organic Chemistry Series, Pergamon Press; Oxford: 1993.  Chap. 6. p.236-245  

<A NAME="RG41407ST-6">6</A> See ref. 5, Chap 9 and: Nájera C. Yus M. Tetrahedron  1999,  55:  10547 

See, for instance:

<A NAME="RG41407ST-7A">7a</A> De Lucchi O. Luchini V. Pasquato L. Modena G. J. Org. Chem.  1984,  49:  596 

<A NAME="RG41407ST-7B">7b</A> De Lucchi O. Modena G. Tetrahedron  1984,  40:  2585 

<A NAME="RG41407ST-7C">7c</A> De Lucchi O. Licini G. Pasquato L. Senta M. Tetrahedron Lett.  1988,  29:  831 

<A NAME="RG41407ST-7D">7d</A> Azzena U. Cossu S. De Lucchi O. Melloni G. Tetrahedron Lett.  1989,  30:  1845 

For selected accounts, see:

<A NAME="RG41407ST-8A">8a</A> Dittmer DC. Takashina N. Tetrahedron Lett.  1964,  3809 

<A NAME="RG41407ST-8B">8b</A> Sridhar M. Krishna KL. Sriniras K. Rao JM. Tetrahedron Lett.  1998,  39:  6529 

For selected accounts, see:

<A NAME="RG41407ST-9A">9a</A> Glass RS. Smith DL.
J. Org. Chem.  1974,  39:  3712 

<A NAME="RG41407ST-9B">9b</A> Hanack M. Massa F. Tetrahedron Lett.  1977,  661 

<A NAME="RG41407ST-9C">9c</A> Riera A. Martí M. Moyano A. Pericás MA. Santamaría J. Tetrahedron Lett.  1990,  31:  2173 

<A NAME="RG41407ST-9D">9d</A> Back TG. Parvez M. Zhai H. J. Org. Chem.  2006,  71:  5254 

Rickborn et al. reported the synthesis of 7e (99% isolated yield, Scheme 3) by reaction of IBF generated from acetal 8 and (E)-1,2-bisphenylsulfonylethylene.^10a On the other hand, Padwa et al. reported the capture of the isobenzofuran 10 generated from sulfoxide 9, with the same dienophilic reagent to give 11 as 1:1 diastereoisomeric mixture (69%).^10b See:

<A NAME="RG41407ST-10A">10a</A> Mirsadeghi S. Rickborn B. J. Org. Chem.  1985,  50:  4340 

<A NAME="RG41407ST-10B">10b</A> Padwa A. Cochran JE. Kappe CD. J. Org. Chem.  1996,  61:  3706 

<A NAME="RG41407ST-11">11</A> Synthesized according to: Cho YH. Fayol A. Lautens M. Tetrahedron: Asymmetry  2006,  17:  416 

<A NAME="RG41407ST-12">12</A>

General Procedure
To equimolecular amounts of tetrazine 3, compounds 4 or 5, and sulfone 6, DMSO (10 mL/mmol) was added. The reaction mixture was stirred under Ar at r.t. for 24 h. After this time the reaction mixture was extracted with Et₂O (5 mL) and washed with H₂O (3 × 10 mL). The organic phase was dried over MgSO₄. After removal of the solvent under reduced pressure, the crude product was purified by column chromatography (SiO₂, hexane-EtOAc, 7:3).

<A NAME="RG41407ST-13">13</A>

Compounds 7 were characterized by IR, ¹H NMR, and ¹³C NMR spectra and mass spectral analysis. In the case of compound 7e, spectroscopic data matched with those previously reported. See ref. 10a.

<A NAME="RG41407ST-14">14</A>

Determined by ¹H NMR integration. Key signals: exo adduct: H₂, δ = 3.16 ppm, dd; endo adduct: H₂, δ = 3.96 ppm, dt.

<A NAME="RG41407ST-15">15</A>

Determined by ¹H NMR integration. Key signals: exo adduct: H₂, δ = 3.28 ppm, dd; endo adduct: H₂, δ = 4.00 ppm, dt.