Chiral Naphthyl-C2-Indole as Scaffold for Phosphine Organocatalysis: Application in Asymmetric Formal [4 + 2] Cycloaddition Reactions
作者:Tingting He、Lei Peng、Shan Li、Fangli Hu、Chuandong Xie、Shengli Huang、Shiqi Jia、Wenling Qin、Hailong Yan
DOI:10.1021/acs.orglett.0c02519
日期:2020.9.4
naphthyl-C2-indole bifunctional phosphine organocatalyst in stereoselective formal [4 + 2] cycloadditionreactions were reported. The chiral naphthyl-C2-indole skeleton was introduced to bifunctional phosphine organocatalysis for the first time, and excellent stereocontrol was achieved in two types of formal [4 + 2] cycloadditionreactions. With the optimal catalyst, a series of chiral spirooxindole and hydrodibenzofuran
1,3-Dioxa-[3,3]-sigmatropic Oxo-Rearrangement of Substituted Allylic Carbamates: Scope and Mechanistic Studies
作者:Maddalen Agirre、Sylvain Henrion、Ivan Rivilla、José I. Miranda、Fernando P. Cossío、Bertrand Carboni、José M. Villalgordo、François Carreaux
DOI:10.1021/acs.joc.8b01320
日期:2018.12.21
alkenyl-substituted allylic alcohols with activated isocyanates is reported. The reorganization of bonds is highly dependent on the electron density of the aromatic ring and the nature of isocyanate used. This metal-free tandem reaction from branched allyl alcohols initiated by a carbamoylation reaction and followed by a sigmatropic rearrangement thus offers a new access to (E)-cinnamyl and conjugated (E,E)-diene
Access to 1,3‐Dinitriles by Enantioselective Auto‐tandem Catalysis: Merging Allylic Cyanation with Asymmetric Hydrocyanation
作者:Jinguo Long、Rongrong Yu、Jihui Gao、Xianjie Fang
DOI:10.1002/anie.202000704
日期:2020.4.20
Enantioselective auto-tandem catalysis represents a challenging yet highlight attractive topic in the field of asymmetriccatalysis. In this context, we describe a dual catalytic cycle that mergesallyliccyanation and asymmetrichydrocyanation. The one-pot conversion of a broad array of allylic alcohols into their corresponding 1,3-dinitriles proceeds in good yield with high enantioselectivity. The
Palladium-catalyzed regiocontrolled and stereoselective alkylations of bis(trifluoroethyl) malonates with dienyl alcohols
作者:James M. Takacs、Xun-tian Jiang、Alexei P. Leonov
DOI:10.1016/s1268-7731(03)00074-2
日期:2003.9
The triethylborane-promoted and palladium-catalyzed reactions of 2,4-dienyl alcohols or the corresponding isomeric divinyl alcohols with bis(trifluoroethyl) malonates provide an improved method for the regio- and stereoselective dienylation of malonates. The phosphine ligand is an important control element in the reaction. Combinations of Pd(OAc)(2) with BIPHEP or BINAP give dienylated malonates in good yield and higher isomeric purity than the traditional combination of Pd(OAc)(2) and Ph3P affords in the catalyzed reactions of dienyl acetates. (C) 2003 Elsevier Ltd. All rights reserved.
Reductive Aldol Coupling of Divinyl Ketones via Rhodium-Catalyzed Hydrogenation: syn-Diastereoselective Construction of β-Hydroxyenones
作者:Soo Bong Han、Michael J. Krische
DOI:10.1021/ol0624023
日期:2006.11.1
Catalytic hydrogenation of divinyl ketones 1a and 1e in the presence of diverse aldehydes 2a-e at ambient temperature and pressure using cationic rhodium catalysts ligated by tri-2-furyl phosphine enables formation of aldol products 3a-e and 5a-e, respectively, with high levels of syn diastereoselection. Through an assay of counterions (Rh(COD)(2)X), Rh(COD)(2)SbF6 is identified as the optimum precatalyst for reductive aldol couplings of this type. For para-substituted styryl vinyl ketones 1b-e, a progressive increase in isolated yield is observed for electron-releasing para substituents.