Chemo- and Enantioselective Brønsted Acid-Catalyzed Reduction of α-Imino Esters with Catecholborane
作者:Dieter Enders、Andreas Rembiak、Bianca Anne Stöckel
DOI:10.1002/adsc.201300352
日期:2013.7.8
The chemo‐ and enantioselectivereduction of α‐imino esters with catecholborane has been developed employing 10 mol% of an enantiopure BINOL‐based phosphoric acid as organocatalyst. Various differently substituted aromatic α‐amino acid derivatives can be achieved in almost quantitative yields and very good to excellent enantioselectivities of up to 96% ee under mild reaction conditions.
A deuterium‐labelingreaction of nitroalkanes in deuterium oxide and the subsequent nitroaldol reaction have been accomplished under basic and organocatalytic conditions to provide the deuterium‐labeled β‐nitroalcohols in high yields and high deuterium contents. β‐Deuterated β‐nitroalcohols could be smoothly obtained from the reaction of nitroalkanes and various electrophiles using the easily‐removal
Catalytic Asymmetric Transfer Hydrogenation of α-Ketoesters with Hantzsch Esters
作者:Jung Woon Yang、Benjamin List
DOI:10.1021/ol0624373
日期:2006.11.1
C2-symmetric chiral copper(II)-bisoxazolines function as alcohol dehydrogenase mimics and catalyze highly enantioselective transferhydrogenations of alpha-ketoesters with Hantzsch esters as a synthetic NADH analogue to give alpha-hydroxy esters in excellent enantioselectivities. [reaction: see text].
Enantiocontrol by assembled attractive interactions in copper-catalyzed asymmetric direct alkynylation of α-ketoesters with terminal alkynes: OH⋯O/sp<sup>3</sup>-CH⋯O two-point hydrogen bonding combined with dispersive attractions
作者:Martin C. Schwarzer、Akane Fujioka、Takaoki Ishii、Hirohisa Ohmiya、Seiji Mori、Masaya Sawamura
DOI:10.1039/c8sc00527c
日期:——
Copper-catalyzed asymmetric directalkynylation of α-ketoesters with terminal alkynes with chiral prolinol–phosphine ligands, most preferably (αR,2S)-1-(2-dicyclohexylphosphinobenzyl)-α-neopentyl-2-pyrrolidinemethanol, afforded various enantioenriched chiral propargylic tertiary alcohols. Quantum-chemical calculations using the BP86 density functional including Grimme's empirical dispersion correction
铜催化 α-酮酯与末端炔烃与手性脯氨醇-膦配体,最优选 (α R ,2 S )-1-(2-二环己基膦基苄基)-α-新戊基-2-吡咯烷甲醇的不对称直接炔基化,提供了各种对映体富集的手性炔丙基叔醇。使用 BP86 密度泛函(包括 Grimme 经验色散校正)的量子化学计算 [DF-BP86-D3(BJ)-PCM( t BuOH)/TZVPP//DF-BP86-D3(BJ)/SVP] 显示 OH⋯ 的出现手性配体和处于立体决定过渡态的酮酯的羰基之间的O/sp 3 -CH⋯O两点氢键。结合定向酮酯底物的氢键相互作用,手性配体(P-环己基)和有利过渡态的酮酯之间的色散吸引力,而不是不利过渡态的空间排斥,解释了不对称铜催化的对映选择性。
Formation of Complex α-Imino Esters via Multihetero-Cope Rearrangement of α-Keto Ester Derived Nitrones
作者:Samuel Bartlett、Kimberly Keiter、Blane Zavesky、Jeffrey Johnson
DOI:10.1055/s-0037-1610391
日期:2019.1
the Department of Chemistry at UNC Chapel Hill, which celebrated its bicentennial in 2018. Published as part of the 50 Years SYNTHESIS – Golden Anniversary Issue Abstract A sequential benzoylation and multihetero-Cope rearrangement of α-keto ester derived nitrones has been developed. The reaction furnishes a diverse array of complex α-imino ester derivatives. The products can be transformed into amino