Phosphine-Catalyzed [3+2] Annulation of Cyanoallenes

Abstract

Cyanoallenes were successfully used in organophosphine-catalyzed [3+2]-type annulation to give cyano-substituted dihydropyrroles in good yield. Chiral phosphines were also screened, leading to some initial results in the asymmetric version of cyano­allene-based annulations.

Key words

cyanoallene - [3+2] annulation - phosphine - organo­catalysis - dihydropyrrole

References and Notes

• 1 Lovas FJ. Remijan AJ. Hollis JM. Jewell PR. Snyder LE. Astrophys. J.  2006,  637:  L37 
• 2a Brandsma L. Best Synthetic Methods: Synthesis of Acetylenes, Allenes and Cumulenes: Methods and Techniques   Elsevier Academic Press; Boston / Amsterdam: 2004. 
• 2b Brandsma L. Verkruijsse HD. Synthesis of Acetylenes, Allenes and Cumulenes, a Laboratory Manual in Studies in Organic Chemistry   Vol. 8:  Elsevier; Amsterdam: 1981. 
• 2c Kurtz P. Gold H. Disselnkötter H. Justus Liebigs Ann. Chem.  1959,  624:  1 
• 2d For a review on allene syntheses, see: Brummond KM. DeForrest JE. Synthesis  2007,  795 
• For a few selected examples on the use of 1, see:
• 3a Danheiser RL. Casebier DS. Huboux AH. J. Org. Chem.  1994,  59:  4844 
• 3b Loebach JL. Bennet DM. Danheiser RL. J. Org. Chem.  1998,  63:  8380 
• 3c Pasto DJ. L’Hermine G. J. Org. Chem.  1990,  55:  685 
• For examples, see:
• 4a Ma S. Chem. Rev.  2005,  105:  2829 
• 4b Ma S. Acc. Chem. Res.  2003,  36:  701 
• 5a Zhang C. Lu X. J. Org. Chem.  1995,  60:  2906 
• 5b Zhu G. Chen Z. Jiang Q. Xiao D. Cao P. Zhang X. J. Am. Chem. Soc.  1997,  119:  3836 
• 5c Xu Z. Lu X. J. Org. Chem.  1998,  63:  5031 
• 5d Zhu X.-F. Henry CE. Kwon O. Tetrahedron  2005,  61:  6276 
• 5e Zhu X.-F. Lan J. Kwon O. J. Am. Chem. Soc.  2003,  125:  4716 
• 5f Castellano S. Fiji HDG. Kinderman SS. Watanabe M. de Leon P. Tamanoi F. Kwon O. J. Am. Chem. Soc.  2007,  129:  5843 
• 5g Watanabe M. Fiji HDG. Guo L. Chan L. Kinderman SS. Slamon DJ. Kwon O. Tamanoi F. J. Biol. Chem.  2008,  283:  9571 
• For more examples, see the following reviews:
• 5h Ye L.-W. Zhou J. Tang Y. Chem. Soc. Rev.  2008,  37:  1140 
• 5i Cowen BJ. Miller SJ. Chem. Soc. Rev.  2009,  38:  3102 
• 6 Horner L. Jurgeleit W. Klüpfel K. Justus Liebigs Ann. Chem.  1955,  591:  108 
• For an example, see:
• 8a Trost BM. Marrs CM. J. Am. Chem. Soc.  1993,  115:  6636 
• 8b Trost BM. Silverman SM. J. Am. Chem. Soc.  2010,  132:  8238 
• 12a Marinetti A. Voituriez A. Synlett  2010,  174 
• 12b Jean L. Marinetti A. Tetrahedron Lett.  2006,  47:  2141 
• 12c Fleury-Brégeot N. Jean L. Retailleau P. Marinetti A. Tetrahedron  2007,  63:  11920 
• 12d Wilson JE. Fu GC. Angew. Chem. Int. Ed.  2006,  45:  1426 
• 12e Wurz RP. Fu GC. J. Am. Chem. Soc.  2005,  127:  12234 
• 12f Cowen BJ. Miller SJ. J. Am. Chem. Soc.  2007,  129:  10988 
• 12g Wallace DJ. Sidda RL. Reamer RA. J. Org. Chem.  2007,  72:  1051 
• 12h Fang Y.-Q. Jacobsen EN. J. Am. Chem. Soc.  2008,  130:  5660 
• 12i Voituriez A. Panossian A. Fleury-Brégeot N. Retailleau P. Marinetti A. J. Am. Chem. Soc.  2008,  130:  14030 

7

Representative Experiment: To a stirred solution of imine 6 (4.08 mmol) in anhyd benzene (20 mL) at r.t. were added triphenylphosphine (0.8 mmol, 20 mol%) and cyanoallene (70% w/w solution in toluene, 4.9 mmol, 1.2 equiv). The solution was stirred until the imine was consumed (ca. 16 h) as judged by TLC (hexanes-EtOAc, 1:1). The solution was concentrated and the crude oil was purified by column chromatography (hexanes-EtOAc, 4:1-1:1). For further details, see the supplementary material.

9

The cis configuration was concluded after comparison of the ^¹H NMR spectra with the reported literature data for similar allenoates; see ref. 5d.

10

For the synthesis of 10 and 12, see refs. 2a and 2b.

11

We noticed the successful ferrocenophanes (Marinetti), phosphepines (Fu), and phosphinothioureas (Jacobsen) in [3+2] annulations, but did not test these in our survey, see ref. 12.