Development of a New Lewis Acid-Catalyzed [3,3]-Sigmatropic Rearrangement: The Allenoate-Claisen Rearrangement
作者:Tristan H. Lambert、David W. C. MacMillan
DOI:10.1021/ja028090q
日期:2002.11.1
A new Lewis acid-catalyzedClaisenrearrangement has been developed that allows the stereoselective construction of beta-amino-alpha,beta,epsilon,zeta-unsaturated-gamma,delta-disubstituted esters from simple allylic amines and allenoate esters. This reaction, which is contingent upon the use of Lewis acid, can be conducted with a range of metal salts (Yb(OTf)3, AlCl3, Sn(OTf)2, Cu(OTf)2, MgBr2.Et2O
Convenient synthesis of allenyl esters and amides by palladium catalyzed alkoxy- and amido-carbonylation of allenyl and propynyl halides
作者:Nguyen D. Trieu、Cornelis J. Elsevier、Kees Vrieze
DOI:10.1016/0022-328x(87)80416-3
日期:1987.5
Allenylesters R1R2C=C=C(H)C(O)R (R = OMe) or amides (R = NEt2) are formed with excellent selectivities and in good yields by carbonylation of propynyl and allenyl halides at 1–20 bar CO pressure in benzene, in the presence of MeOH or HNEt2 and 1% of Pd(PPh3)4 or trans-Me2C=C=C(H)Pd(PPh3)2Br. Possible organometallic intermediates are discussed.
通过丙炔基和烯丙基卤化物在1处羰基化,可以形成具有优异选择性和高收率的烯丙基酯R 1 R 2 C = C = C(H)C(O)R(R = OMe)或酰胺(R = NEt 2)。在MeOH或HNEt 2和1%Pd(PPh 3)4或反式-Me 2 C = C = C = C(H)Pd(PPh 3)2 Br存在下,苯中的–20 bar CO压力。讨论了可能的有机金属中间体。
A copper-catalyzed diastereoselective O-transfer reaction of <i>N</i>-vinyl-α,β-unsaturated nitrones with ketenes into γ-lactones through [5 + 2] cycloaddition and N–O bond cleavage
作者:Jun-Yi Liao、Qing-Yan Wu、Xiuqiang Lu、Ning Zou、Cheng-Xue Pan、Cui Liang、Gui-Fa Su、Dong-Liang Mo
DOI:10.1039/c9gc01811e
日期:——
densely functionalized γ-lactones was developed in good to excellent yields with high diastereoselectivity from easily available N-vinyl-α,β-unsaturated nitrones and ketenes. The reaction involves copper-catalyzed [5 + 2] cycloaddition, N–O bond cleavage, 6π electron cyclization, and aromatization to afford various γ-(pyridin-2-yl)lactones over four step transformations in a single flask. The present
Eine einfache Allencarbonsäureester-Synthese mittels der<i>Wittig</i>-Reaktion
作者:Robert W. Lang、Hans-Jürgen Hansen
DOI:10.1002/hlca.19800630215
日期:1980.3.5
A Simple Synthesis of Alkyl Allenecarboxylates (Allenic Esters) by the Wittig-Reaction
Wittig反应合成烷基烯丙基羧酸盐(烯基酯)。
Regio- and stereoselective copper-catalyzed β-borylation of allenoates by a preactivated diboron
作者:Steven B. Thorpe、Xi Guo、Webster L. Santos
DOI:10.1039/c0cc02270e
日期:——
A mild and efficient copper-catalyzed borylation of electron deficient allenoates using an sp2âsp3 mixed hybridized diboron regioselectively installs a boron moiety on the β-position with exclusive (Z)-double bond geometry.