Asymmetric Allylboration of Ketones Catalyzed by Chiral Diols
作者:Sha Lou、Philip N. Moquist、Scott E. Schaus
DOI:10.1021/ja0651308
日期:2006.10.1
Chiral BINOL-derived diols catalyze the enantioselective asymmetricallylboration of ketones. The reaction requires 15 mol % of 3,3‘-Br2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (76−93%) and high enantiomeric ratios (95:5−99.5:0.5). High diastereoselectivities (dr ≥ 98:2) and enantioselectivities (er ≥ 98:2) are obtained
<i>B</i>-Allyl-10-Ph-9-borabicyclo[3.3.2]decanes: Strategically Designed for the Asymmetric Allylboration of Ketones
作者:Eda Canales、K. Ganeshwar Prasad、John A. Soderquist
DOI:10.1021/ja053865r
日期:2005.8.24
bicyclic structure. In addition to providing the homoallylic alcohols 6 efficiently (70-92%), the procedure also permits the efficient recovery of the chiral boron moiety (67-82%) as an air-stable crystalline N-methylpseudoephedrine complex 4 for the direct regeneration of 1 with allylmagnesium bromide in ether (98%). The reagent gives predictable stereochemistry, providing a strategically designed "chiral
Practical and Broadly Applicable Catalytic Enantioselective Additions of Allyl-B(pin) Compounds to Ketones and α-Ketoesters
作者:Daniel W. Robbins、KyungA Lee、Daniel L. Silverio、Alexey Volkov、Sebastian Torker、Amir H. Hoveyda
DOI:10.1002/anie.201603894
日期:2016.8.8
catalytic additions of easy‐to‐handle allyl‐B(pin) (pin=pinacolato) compounds to ketones and acyclic α‐ketoesters was developed. Accordingly, a large array of tertiary alcohols can be obtained in 60 to >98 % yield and up to 99:1 enantiomeric ratio. At the heart of this development is rational alteration of the structures of the small‐molecule aminophenol‐based catalysts. Notably, with ketones, increasing
Design and Synthesis of Modular Oxazoline Ligands for the Enantioselective Chromium-Catalyzed Addition of Allyl Bromide to Ketones
作者:Jeremie J. Miller、Matthew S. Sigman
DOI:10.1021/ja068915m
日期:2007.3.1
By systematically evaluating ligand diastereomers using a modular oxazoline template, a new ligand has been identified leading to the discovery of the first example of a chromium-catalyzed enantioselective allylation of ketones using allylic bromides.