Tandem Asymmetric Cyclopropanation/Cope Rearrangement. A Highly Diastereoselective and Enantioselective Method for the Construction of 1,4-Cycloheptadienes
作者:Huw M. L. Davies、Douglas G. Stafford、Brian D. Doan、Jeffrey H. Houser
DOI:10.1021/ja974201n
日期:1998.4.1
rhodium(II) (N-dodecylbenzenesulfonyl)prolinate (Rh2(S-DOSP)4, 1) in the presence of dienes results in a direct and highly enantioselective method for the formation of cis-divinylcyclopropanes. Combination of this process with a subsequent Cope rearrangement results in a highly enantioselective synthesis of a variety of cycloheptadienes containing multiple stereogenic centers.
在二烯存在下,通过铑 (II) (N-十二烷基苯磺酰基) 脯氨酸 (Rh2(S-DOSP)4, 1) 分解乙烯基重氮乙酸酯,可以直接且高度对映选择性地形成顺式二乙烯基环丙烷。该过程与随后的 Cope 重排相结合,导致多种含有多个立体中心的环庚二烯的高度对映选择性合成。
Highly Regio- and Enantioselective Formal [3 + 2]-Annulation of Indoles with Electrophilic Enol Carbene Intermediates
作者:Changcheng Jing、Qing-Qing Cheng、Yongming Deng、Hadi Arman、Michael P. Doyle
DOI:10.1021/acs.orglett.6b02192
日期:2016.9.16
formal [3 + 2]-annulation reactions of indoles and electrophilic enol carbenes. High enantioselectivity and exclusive regiocontrol occurred with enoldiazoacetamides using a less sterically encumbered prolinate-ligated dirhodium(II) catalyst in reactions with N-substituted indoles without substituents at the 2- or 3-positions via a selective vinylogousaddition process. In this transformation, donor–acceptor
Abstract Three-component Mukaiyama–Mannich reaction of aldehydes, amines, and silyl enol diazoacetoacetate was efficiently carried out to afford δ-amino substituted-α-diazoacetoacetate derivatives catalyzed by 5 mol% of MgI2 etherate (MgI2•(OEt2)n) under mild and neutral reaction conditions in good to excellent yields. GRAPHICAL ABSTRACT
Catalytic Addition Methods for the Synthesis of Functionalized Diazoacetoacetates and Application to the Construction of Highly Substituted Cyclobutanones
作者:Michael P. Doyle、Kousik Kundu、Albert E. Russell
DOI:10.1021/ol052003s
日期:2005.11.1
[reaction: see text] Methyl 3-(trialkylsilanyloxy)-2-diazo-3-butenoate undergoes Lewis acid-catalyzed Mukaiyamaaldol addition with aromatic and aliphatic aldehydes in the presence of low catalytic amounts of Lewis acids in nearly quantitative yields. Scandium(III) triflate is the preferred catalyst and, notably, addition proceeds without decomposition of the diazo moiety. Diazoacetoacetate products
Ruthenium-Catalyzed One-Pot Carbenoid N−H Insertion Reactions and Diastereoselective Synthesis of Prolines
作者:Qing-Hai Deng、Hai-Wei Xu、Angella Wing-Hoi Yuen、Zhen-Jiang Xu、Chi-Ming Che
DOI:10.1021/ol800087p
日期:2008.4.1
3-hydroxyprolines and various other amino esters are conveniently prepared by [RuCl2(p-cymene)]2-catalyzed one-pot intramolecular and intermolecular carbenoid N-H insertionreactions, respectively, and the prolines are formed with high diastereoselectivities. The catalytic reactions are tolerant toward air/moisture, and the product yields are insensitive to the organic solvents used.