CpRuCl(PPh₃)₂/MeI Catalyst System for the [2+2] Cycloaddition of Norbornenes with Disubstituted Alkynes

Abstract

CpRu(PPh₃)₂I generated in situ by mixing CpRu(PPh₃)₂Cl and methyl iodide catalyzed the [2+2] cycloaddition of norbornene (or norbornadiene) and disubtituted alkynes to afford functionalized cyclobutenes.

ruthenium catalyst - cycloaddition - alkynes - bicyclic alkenes - cyclobutenes

References

<A NAME="RG23703ST-1A">1a</A> Lautens M. Klute W. Tam W. Chem. Rev.  1996,  96:  49 

<A NAME="RG23703ST-1B">1b</A> Ojima I. Tzamarioudaki M. Li Z. Donovan RJ. Chem. Rev.  1996,  96:  635 

<A NAME="RG23703ST-2A">2a</A> Woodward RB. Hoffmann R. The Conservation of Orbital Symmetry   Academic Press; New York: 1970. 

<A NAME="RG23703ST-2B">2b</A> Woodward RB. Hoffmann R. Angew. Chem., Int. Ed. Engl.  1969,  8:  781 

<A NAME="RG23703ST-3A">3a</A> Greco A. Carbonaro A. Dall’Asta G. J. Org. Chem.  1970,  35:  271 

<A NAME="RG23703ST-3B">3b</A> Rosemblum M. Scheck D. Organometallics  1982,  1:  397 

<A NAME="RG23703ST-4A">4a</A> Schrauzer GN. Glockner P. Chem. Ber.  1964,  97:  2451 

<A NAME="RG23703ST-4B">4b</A> Noyori R. Ishigami T. Hayashi N. Takaya H. J. Am. Chem. Soc.  1973,  95:  1674 

<A NAME="RG23703ST-4C">4c</A> Kiji J. Yoshikawa S. Sasakawa E. Nishimura S. Furukawa J. J. Organomet. Chem.  1974,  80:  267 

<A NAME="RG23703ST-4D">4d</A> Huang DJ. Rayabarapu DK. Li LP. Sambaiah T. Cheng CH. Chem.-Eur. J.  2000,  6:  3706 

<A NAME="RG23703ST-4E">4e</A> Lautens M. Edwards LG. Tam W. Lough AJ. J. Am. Chem. Soc.  1995,  117:  10276 

<A NAME="RG23703ST-5A">5a</A> Coulson DR. J. Org. Chem.  1972,  37:  1253 

<A NAME="RG23703ST-5B">5b</A> Trost BM. Yanai M. Hoogsteen K. J. Am. Chem. Soc.  1993,  115:  5294 

<A NAME="RG23703ST-5C">5c</A> Tsukuda N. Sato T. Inoue Y. Tetrahedron Lett.  2000,  41:  4181 

<A NAME="RG23703ST-6A">6a</A> Mitsudo T. Kokuryo K. Takegami Y. J. Chem. Soc., Chem. Commun.  1976,  722 

<A NAME="RG23703ST-6B">6b</A> Mitsudo T. Kokuryo K. Shinsugi T. Nakagawa Y. Watanabe Y. Takegami Y. J. Org. Chem.  1979,  44:  4492 

<A NAME="RG23703ST-6C">6c</A> Russell RA. Longmore RW. Weerasuria KDV. Warrener RN. Aust. J. Chem.  1991,  44:  1341 

<A NAME="RG23703ST-6D">6d</A> Warrener RN. Groundwater P. Pitt IG. Butler DN. Russell RA. Tetrahedron Lett.  1991,  32:  1885 

<A NAME="RG23703ST-6E">6e</A> Winling A. Russell RA. J. Chem. Soc., Perkin Trans. 1  1998,  3921 

<A NAME="RG23703ST-7">7</A> Mitsudo T. Hori Y. Watanabe Y. J. Organomet. Chem.  1987,  334:  157 

<A NAME="RG23703ST-8">8</A> Yi CS. Lee DW. Chen Y. Organometallics  1999,  18:  2043 

<A NAME="RG23703ST-9A">9a</A> Mitsudo T. Naruse H. Kondo T. Ozaki Y. Watanabe Y. Angew. Chem., Int. Ed. Engl.  1994,  33:  580 

<A NAME="RG23703ST-9B">9b</A> Jordan R. Tam W. Org. Lett.  2000,  2:  3031 

<A NAME="RG23703ST-9C">9c</A> Jordan RW. Tam W. Org. Lett.  2001,  3:  2367 

<A NAME="RG23703ST-10">10</A> lvarez P. Gimeno J. Lastra E. Garcia-Granda S. Van der Maelen JF. Bassetti M. Organometallics  2001,  20:  3762 

<A NAME="RG23703ST-11">11</A>

Tenaglia, A.; Giordano, L. submitted for publication.

<A NAME="RG23703ST-12">12</A> Bruce MI. Windsor N. J. Aust. J. Chem.  1977,  30:  1601 

<A NAME="RG23703ST-13">13</A> Kulawiec RJ. Faller JW. Crabtree RH. Organometallics  1990,  9:  745 

<A NAME="RG23703ST-14">14</A>

The structure of CpRuI(PPh₃)₂ was secured by an X-ray analysis and deposited with the Cambridge Crystallographic Data Centre (CCDC 219110). The coordinates can be obtained, on request, from the Director, Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge, CB2, 1EZ, UK.

For the preparation of CpRuI(PPh₃)₂, see:

<A NAME="RG23703ST-15A">15a</A> Blackmore T. Bruce MI. Stone FGA. J. Chem. Soc.  1971,  2376 

<A NAME="RG23703ST-15B">15b</A> For similar observations with CH₂I₂, see: Park JH. Koh JH. Park J. Organometallics  2001,  20:  1892 

For a sporadic use of CpRuI(PPh₃)₂ as catalyst for carbene-carbene coupling and cyclopropanation, see:

<A NAME="RG23703ST-16A">16a</A> Baratta W. Del Zotto A. Rigo P. Organometallics  1999,  18:  5091 

<A NAME="RG23703ST-16B">16b</A> Baratta W. Herrmann WA. Kratzer RM. Rigo P. Organometallics  2000,  19:  3664 

<A NAME="RG23703ST-17">17</A>

Typical Procedure: A solution of CpRuCl(PPh₃)₂ (36.3 mg, 0.05 mmol) and methyl iodide (49.6 mg, 22 µL, 0.35 mmol) in dioxane (2 mL) was stirred for 10 min in a Schlenk tube under an Ar atmosphere. A solution of norbornene 1 (282 mg, 3 mmol) and alkyne (1 mmol) in dioxane (6 mL) was added and the mixture was heated at 90 °C until completion (TLC monitoring). Dioxane was evaporated in vacuo and the crude product was purified by SiO₂ column chromato-graphy.

<A NAME="RG23703ST-18">18</A>

All new compounds exhibited satisfactory ¹H and ¹³C NMR and IR spectral data as well as satisfactory combustion analysis. The following physical data are representative:
Tricyclo[4.2.1.0 [2] [5] ]non-3-ene-3,4-diyldimethanol 4a. White solid, R_f = 0.73 (CH₂Cl₂/MeOH 9/1). Mp 57-58 °C. IR (KBr): 3307, 2946, 1665 cm^-1. ¹H NMR (200 MHz, CDCl₃): δ = 1.01 (m, 3 H), 1.51 (m, 3 H), 1.96 (m, 2 H), 2.31 (br s, 2 H), 2.84 (m, 2 H, OH), 4.11 (br s, 4 H). ¹³C NMR (50 MHz, CDCl₃): δ = 28.1 (t), 30.3 (t), 33.6 (d), 46.3 (d), 58.7 (t), 140.2 (s). Anal. Calcd for C₁₁H₁₆O₂: C, 73.30; H, 8.95. Found: C, 73.12; H, 8.84.
Tricyclo[4.2.1.0 [2] [5] ]nona-3,7-diene-3,4-diyldimethanol 5a. White solid, R_f = 0.70 (CH₂Cl₂/MeOH 9/1). Mp 59-60 °C. IR (KBr): 3293, 3056, 2966, 1654 cm^-1. ¹H NMR (200 MHz, CDCl₃): δ = 1.31 (br d, J = 9.0 Hz, 1 H), 1.43 (br d, J = 9.0 Hz, 1 H), 2.18 (br s, 2 H), 2.43 (br s, 2 H), 3.68 (m, 2 H, OH), 4.20 (br s, 4 H), 6.10 (t, J = 1.6 Hz, 2 H). ¹³C NMR (50 MHz, CDCl₃): δ = 38.2 (d), 39.6 (t), 42.6 (d), 59.1 (t), 135.4 (d), 140.2 (s). Anal. Calcd for C₁₁H₁₄O₂: C, 74.13; H, 7.92. Found: C, 73.93; H, 7.78.

<A NAME="RG23703ST-19A">19a</A> Bickford CC. Johnson TJ. Davidson ER. Caulton KG. Inorg. Chem.  1994,  33:  1080 

<A NAME="RG23703ST-19B">19b</A> Johnson TJ. Folting K. Streib WE. Martin JD. Huffman JC. Jackson SA. Eisenstein O. Caulton KG. Inorg. Chem.  1995,  34:  488