研究了路易斯酸催化的烯烃α-溴β-酮酰胺的原子转移自由基环化反应。发现路易斯酸Yb(OTf)3或Mg(ClO 4)2不仅促进环化反应,而且在环化产物中产生优异的反式立体控制。在Et 3 B / O 2存在下,路易斯酸Yb(OTf)3或Mg(ClO 4)2在-78°C下催化,C-烯烃β-酮酰胺的环化反应提供了环酮,而N的环化反应烯烃的β-酮酰胺导致形成γ-内酰胺,其可被转化为3-氮杂-双环[3,1,0]己-2-基。
A 4-Dimethylaminopyridine-Catalyzed Aminolysis of β-Ketoesters. Formation of β-Ketoamides
作者:Janine Cossy、Annie Thellend
DOI:10.1055/s-1989-27383
日期:——
Alkyl 3-oxoalkanoates (ß-ketoesters) react with amines in the presence of a catalytic amount of 4-dimethylaminopyridine (DMAP) under mild conditions to form 3-oxoalkanamides (ß-ketoamides) in good yields.
Cyclic β-ketoamides undergo a regioselective 1,2-addition to α,β-unsaturated aldehydes leading to synthetically valuable cycloalkenones by a stereoselective one-pot γ-allylidenation promoted by DBU in MeOH.
Intramolecular Ene Reactions. Stereo- and Enantioselective Synthesis of Spirolactams through Thermolysis of Enamino Carboxamides
作者:Janine Cossy、Abdelrrahim Bouzide、Michel Pfau
DOI:10.1021/jo970257o
日期:1997.10.1
thermal rearrangement of tertiary and secondary enamino carboxamides has been developed. The enamine group of an enamino carboxamide, in which no electron-withdrawing group is present in the enophile, can be involved in the ene reaction and the enamino carboxamide can be transformed into enamino or imino spirolactams. In the case of secondary carboxamido enamines, the diastereoselectivity is higher than 98%
Stereoselective formation of spirolactams by intramolecular ene reaction
作者:J. Cossy、A. Bouzide
DOI:10.1016/s0040-4039(00)92226-3
日期:1992.4
A new and facile access to spirolactams based on the thermal rearrangements of N,N-unsaturated dialkyl-β-ketoamides and N,N-unsaturated dialkyl enaminoamides has been developed.
The oxidative radical cyclization of active methylene derivatives containing allyl groups as radical acceptors proceeded with the use of FeCl3 as a mild oxidant. The FeCl3-promoted cyclization reactions of α-substituted active methylene compounds provide a synthetic approach to various γ-lactams containing a quaternary carbon atom.