Enantioselective Synthesis of Spiropentanes from Hydroxymethylallenes
作者:André B. Charette、Eric Jolicoeur、Gregory A. S. Bydlinski
DOI:10.1021/ol0165140
日期:2001.10.1
[reaction: see text]. Hydroxymethylallenes are efficiently converted to the corresponding spiropentanes in high yields and enantiomeric ratios upon treatment with Zn(CH2I)2 and dioxaborolane ligand 1. The reaction also proceeds with complete diastereocontrol. The application of this methodology to the synthesis of spiropentaneacetic acid is also presented.
Gold(I)‐Catalyzed Enantioselective Desymmetrization of 1,3‐Diols through Intramolecular Hydroalkoxylation of Allenes
作者:Weiwei Zi、F. Dean Toste
DOI:10.1002/anie.201508331
日期:2015.11.23
A gold(I)‐catalyzedenantioselectivedesymmetrization of 1,3‐diols was achieved by intramolecularhydroalkoxylation of allenes. The catalyst system 3‐F‐dppe(AuCl)2 /(R)‐C8‐TRIPAg proved to be specifically efficient to promote the desymmetrizing cyclization of 2‐aryl‐1,3‐diols, which have proven challenging substrates in previous reports. Multisubstituted tetrahydrofurans were prepared in good yield
Skeletal Rearrangement in the Zn<sup>II</sup>-Catalyzed [4+2]-Annulation of Disubstituted<i>N</i>-Hydroxy Allenylamines with Nitrosoarenes to Yield Substituted 1,2-Oxazinan-3-one Derivatives
作者:Pankaj Sharma、Rai-Shung Liu
DOI:10.1002/chem.201602579
日期:2016.10.24
reports zinc‐catalyzed [4+2]‐annulation reactions of disubstituted N‐hydroxy allenylamines with nitrosoarenes to afford substituted 1,2‐oxazinan‐3‐ones with a skeletal rearrangement. This annulation is applicable to a reasonable scope of allenylamines and nitrosoarenes. Our control experiments indicate that nitrosobenzene can also implement this annulation through a radical annulation path, but with
Asymmetric Gold-Catalyzed Lactonizations in Water at Room Temperature
作者:Sachin Handa、Daniel J. Lippincott、Donald H. Aue、Bruce H. Lipshutz
DOI:10.1002/anie.201404729
日期:2014.9.26
Asymmetric gold‐catalyzed hydrocarboxylations are reported that show broad substrate scope. The hydrophobic effect associated with in situ‐formed aqueous nanomicelles gives good to excellent ee’s of product lactones. In‐flask product isolation, along with the recycling of the catalyst and the reaction medium, are combined to arrive at an especially environmentally friendly process.
(4+1) vs (4+2): Catalytic Intramolecular Coupling between Cyclobutanones and Trisubstituted Allenes via C–C Activation
作者:Xuan Zhou、Guangbin Dong
DOI:10.1021/jacs.5b09799
日期:2015.10.28
Herein we describe a rhodium-catalyzed (4+1) cyclization between cyclobutanones and allenes, which provides a distinct [4.2.1]-bicyclic skeleton containing two quaternary carbon centers. The reaction involves C-C activation of cyclobutanones and employs allenes as a one-carbon unit. A variety of functional groups can be tolerated, and a diverse range of polycyclic scaffolds can be accessed. Excellent
在此,我们描述了环丁酮和丙二烯之间的铑催化的(4+1)环化,其提供了包含两个季碳中心的独特的[4.2.1]-双环骨架。该反应涉及环丁酮的 CC 活化并采用丙二烯作为一碳单元。可以耐受多种官能团,并且可以获得多种多环支架。TADDOL 衍生的亚磷酰胺配体可实现出色的对映选择性。桥联双环产物可以通过简单的转化进一步官能化或衍生化。