Science of Synthesis

Masson, G.; Zhu, J., Science of Synthesis: Stereoselective Synthesis, (2011) 2, 738.

Only a few examples of tertiary amines without tethered free hydroxy groups have been used in Morita–Baylis–Hillman reactions, leading to Morita–Baylis–Hillman adducts in low to moderate enantioselectivities. Hirama and co-workers reported that the enantiopure 1,4-diazabicyclo[2.2.2]octane derivative, C2-symmetric 2,3-bis(benzyloxymethyl)-1,4-diazabicyclo[2.2.2]octane (‌11‌), catalyzes the Morita–Baylis–Hillman reaction to afford, under high pressure, the product in up to 47% ee (‌Scheme 4‌).[‌18‌,‌19‌] The highest selectivities (75% ee) obtained with this type of catalyst have recently been described by Hayashi and co-workers in the coupling of methyl vinyl ketone with aromatic aldehydes in the presence of chiral diamine ‌12‌, which is easily prepared from l-proline (‌Scheme 4‌).[‌38‌]

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References