CHEM01200604012 Dibakar Goswami - Homi Bhabha National ...

O
R 1 R 2
1a-q
Scheme 2
Allyl bromide / Ga
[bmim][Br]
OH
R 1 R 2
2a-q
In this case also, [bmim][Br] activated Ga metal surface via electron polarization,
but produced (CH 2 CH=CH 2 ) 2 GaBr (III) as active allyl-Ga species, possibly due to the
smaller size of Ga. In view of this, the reaction could be accomplished with 50 mol% of
Ga.
Table 2. Reaction course of Ga-mediated allylation of carbonyls in [bmim][Br] a
Entry Substrate R 1 R 2 Product Time (h) Yield (%)
1 1a C 6 H 5 H 2a 4 84
2. 1b 4-Br-C 6 H 4 H 2b 6 77
3. 1c 3-0Me-C 6 H 4 H 2c 5 84
4. 1d 4-(CH 3 ) 2 CH - C 6 H 4 H 2d 5 87
5. 1e 4-C 6 H 5 -C 6 H 4 H 2e 6 83
6. 1f C 6 F 5 H 2f 5 83
7. 1g C 6 H 5 CH=CH H 2g 12 79
8. 1h (CH 3 ) 2CH H 2h 8 67
9. 1i CH 3 (CH 2 ) 5 H 2i 6 84
10. 1j CH 3 (CH 2 ) 8 H 2j 5 95
11. 1k 3-indolyl H 2k 5 72
12. 1l C 6 H 5 CH 3 2l 10 71
13. 1m C 6 H 5 C 6 H 5 2m 16 67
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