Enantioselective formal [3+3] annulation for the direct construction of bicyclic skeletons with four stereogenic centers.
An enantioselective formal [3+3] annulation reaction of cyclic ketones with enones has been developed. In the presence of 20 mol % of pyrrolidine-thiourea 1a or N-(pyrrolidin-2-ylmethyl)trifluoromethanesulfonamide 1i, the reactions afford bicyclo [3.3.1] adducts in moderate to good yields with good to high enantioselectivities under mild conditions.
Cao
Chun-Li
CL
The State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 200032 Shanghai, China.
Sun
Xiu-Li
XL
Kang
Yan-Biao
YB
Tang
Yong
Y