A Planar-Chiral Rhodium(III) Catalyst with a Sterically Demanding Cyclopentadienyl Ligand and Its Application in the Enantioselective Synthesis of Dihydroisoquinolones
作者:Evgeniya A. Trifonova、Nikita M. Ankudinov、Andrey A. Mikhaylov、Denis A. Chusov、Yulia V. Nelyubina、Dmitry S. Perekalin
DOI:10.1002/anie.201801703
日期:2018.6.25
The rapid development of enantioselective C−H activation reactions has created a demand for new types of catalysts. Herein, we report the synthesis of a novel planar‐chiral rhodium catalyst [(C5H2tBu2CH2tBu)RhI2]2 in two steps from commercially available [(cod)RhCl]2 and tert‐butylacetylene. Pure enantiomers of the catalyst were obtained through separation of its diastereomeric adducts with natural
对映选择性CH活化反应的迅速发展产生了对新型催化剂的需求。在这里,我们报告了从市售[(cod)RhCl] 2和叔丁基乙炔分两步合成新型平面手性铑催化剂[(C 5 H 2 t Bu 2 CH 2 t Bu)RhI 2 ] 2的合成。催化剂的纯对映体是通过将其非对映体加合物与天然(S脯氨酸 催化剂促进了芳基异羟肟酸与应变烯烃的对映选择性反应,从而以高收率(最高97%)和良好的立体选择性(最高ee 95%)提供了二氢异喹诺酮。
Transition Metal-Catalyzed [4 + 2 + 2] Cycloadditions of Bicyclo[2.2.1]hepta-2,5-dienes (Norbornadienes) and Bicyclo[2.2.2]octa-2,5-dienes<sup>1</sup>
作者:Yan Chen、Rattana Kiattansakul、Bin Ma、John K. Snyder
DOI:10.1021/jo010268o
日期:2001.10.1
The transition-metal-catalyzed [4 + 2 + 2] cycloadditions of norbornadienes, bicyclo[2.2.2]octa-2,5-diene, and benzobarrelene with 1,3-butadienes proceed in excellent yields using cobalt-based catalytic systems. Two key distinctions between these [4 + 2 + 2] cycloadditions and the corresponding transition-metal-catalyzed [2 + 2 +2] reactions of norbornadiene are the requirement of a bimetal catalytic
The cycloaddition of phenylglyoxylonitrileoxide to the 7-substitutednorbornadienes a-c gives predominantly the endo isomers, but that to the 8-substituted2-azabicyclo[3.2.1]oct-3,6-dienes a,b the exo isomers.
A new group of non-chemically amplified negative tone water/aqueous base developable (photo) resists based on redistribution of carbon-oxygen bonds in pendant ester groups of the polymers has been found.