Multistep One-Pot Wittig/Nazarov Reaction for Construction of Cyclopentenone with Diazo Compounds and Acid Chlorides
摘要:
A facile multistep one-pot synthesis of single or fused cyclopentenones has been developed. The sequence involves a transition metal-catalyzed ylide formation/Wittig Olefination/Nazarov Cyclization.
Formal [3+2] Cycloaddition of Ketenes and Oxaziridines Catalyzed by Chiral Lewis Bases: Enantioselective Synthesis of Oxazolin-4-ones
作者:Pan-Lin Shao、Xiang-Yu Chen、Song Ye
DOI:10.1002/anie.201003532
日期:2010.11.2
Choose the right cat.: A highly enantioselectivesynthesis of oxazolin‐4‐ones by the formal [3+2] cycloaddition of ketenes and a racemic oxaziridines has been developed (see scheme; cat.=N‐heterocyclic carbenes for disubstituted ketenes or cinchonaalkaloids for monosubstituted ketenes, Ts=4‐toluenesulfonyl).
N-Heterocyclic Carbene Catalysis: Enantioselective Formal [2+2] Cycloaddition of Ketenes and N-Sulfinylanilines
作者:Teng-Yue Jian、Lin He、Cen Tang、Song Ye
DOI:10.1002/anie.201102488
日期:2011.9.19
Sultam of swing: Both enantiomers of 1,2‐thiazetidin‐3‐one oxides were obtained in very good yields with excellent enantioselectivities when using N‐heterocyclic carbene catalysts (see scheme; M.S.=molecular sieves, TBS=tert‐butyldimethylsilyl). The products were easily converted into 3‐oxo‐β‐sultams, α‐mercapto amides, and β‐mercapto amines through oxidation or reduction.
摇摆的结果:使用N杂环卡宾催化剂时,1,2-噻嗪丁-3-氧化物的两种对映体均以非常高的收率获得,并具有出色的对映选择性(参见方案; MS =分子筛,TBS =叔丁基二甲基甲硅烷基)。产物可以通过氧化或还原轻松地转化为3-氧代-β-杜马酰胺,α-巯基酰胺和β-巯基胺。
Enantioselective [4+2] cycloaddition of ketenes and 1-azadienes catalyzed by N-heterocyclic carbenes
作者:Teng-Yue Jian、Pan-Lin Shao、Song Ye
DOI:10.1039/c0cc04839a
日期:——
Optically active highly functionalized 3,4-dihydropyridin-2-ones were synthesized by N-heterocyclic carbene-catalyzed [4+2] enantioselective cycloaddition of ketenes and 1-azadienes.
Pseudo-C2-symmetric chiral phosphorus ylide is designed and synthesized for the enantioselective preparation of allenic esters, amides, ketone, and nitrile. Up to 92% ee is achieved.
设计并合成了伪C 2对称的手性磷叶立德,用于对映体制备烯丙酸酯,酰胺,酮和腈。达到了92%ee。
Enantioselective Synthesis of Indole-Fused Dihydropyranones via Catalytic Cycloaddition of Ketenes and 3-Alkylenyloxindoles
作者:Hui Lv、Xiang-Yu Chen、Li-hui Sun、Song Ye
DOI:10.1021/jo101318u
日期:2010.10.15
Chiral N-heterocyclic carbenes were found to be efficient catalysts for the formal [4+2] cycloaddition reaction of alkyl(aryl)ketenes and 3-alkylenyloxindoles to give the corresponding 3,4-dihydropyrano[2,3-b]indol-2-ones in excellent yields with good diastereo- and enantioselectivities.
发现手性N-杂环卡宾是有效的催化剂,用于烷基(芳基)乙烯酮和3-亚烷基氧吲哚的正式[4 + 2]环加成反应,得到相应的3,4-二氢吡喃并[2,3 - b ]吲哚-2 -具有优异的非对映选择性和对映选择性的高收率化合物。