Manganese η2-complexes as auxiliaries for stereoselective aldol synthesis of allenyl carbinols.
نویسندگان
چکیده
A convenient and robust manganese auxiliary was linked via an η(2)-bond to alkynyl esters and ketones using a mild complexation reaction with methylcyclopentadienyl manganese tricarbonyl. This complex readily underwent aldol reactions with exclusive α-substitution and in good diastereoselectivities especially with aryl ketone substrates. This selectivity has been rationalized using a cyclic transition state model in which the manganese auxiliary plays a critical role in promoting E(O)-geometry of the cumulenolate intermediate.
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عنوان ژورنال:
- Organic letters
دوره 12 21 شماره
صفحات -
تاریخ انتشار 2010