Enantioselective synthesis of functionalized 3,4-dihydropyran derivatives organocatalyzed by a novel fluorinated-diphenylprolinolether

Synthesis of Chiral Cyclopentenones

“…In 2009, a similar approach was reported by Zhong et al Cyclopentenone 381 was obtained in good yield and enantioselectivity using fluorinated diphenylprolinol ether 379 as catalyst (Scheme ).…”

Enantioselective Michael Addition of Cyclic β-Diones to α,β-Unsaturated Enones Catalyzed by Quinine-Based Organocatalysts

“…Therefore, a broad range of conjugate additions of α,β-unsaturated enones with various different nucleophiles have been successfully established with constantly high enantiocontrol [ 15 , 16 , 17 , 18 , 19 ]. However, the asymmetric Michael addition of cyclic 1,3-dicarbonyl compounds [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], except for 4-hydroxycoumarin and its analogues [ 7 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ], to α,β-unsaturated enones, especially chalcones, generally draws less attention in comparison with other type of donors [ 37 , 38 , 39 ], albeit the adducts of such a conjugate addition reaction are versatile precursors to construct several classes of compounds possessing enormous bioactivities [ 40 , 41 ]. Liu and Feng have successfully developed an efficient Michael addition between dimedone and cinnamones employing the unmodified chiral diphenylethylenediamine (DPEN) [ 37 ].…”

“…Based on our continuous interest in asymmetric Michael reactions involving α,β-unsaturated enones [ 42 , 43 , 44 , 45 ], herein we would like to further extend the scope of donor to cyclic β-diones [ 20 , 21 , 22 , 23 , 46 , 47 , 48 , 49 ]. Dimedone and its analogues smoothly react with a variety of α,β-unsaturated enones, furnishing the corresponding adducts in good yields and high levels of optical purities.…”

Enantioselective Synthesis of 3,4-Dihydropyran Derivatives via Organocatalytic Michael Reaction of α,β-Unsaturated Enones

“…Recently, Calter's and our group reported such a procedure of β,γ-unsaturated α-ketoesters by cinchona alkaloid derived pyrimidine organocatalysts and N , N′ -dioxide–Cu(OTf) 2 complex, respectively . Yu’s group utilized a fluorinated diarylprolinol silyl ether catalyst for the reaction of α,β-unsaturated aldehydes . Despite good yield and enantioselectivity obtained, it is worth pointing out that α,β-unsaturated ketones, the common Michael acceptor, have not been applied in this kind of reaction as a consequence of the relatively low reactivity.…”

“…Although the yield of the Michael adduct 4o was slightly reduced, excellent enantioselectivity was maintained (66% yield, 94% ee; Table , entry 15). In the case of o -methoxyl substituted enone 2p , relatively lower yield was obtained as a consequence of 1,2-addition side reaction (Table , entry 16) . The disubstituted aromatic α,β-unsaturated ketones could also be successfully extended, affording the products in moderate yields with 94–95% ee (Table , entries 17 and 18).…”