We have developed a high-efficiency and practical Cu-catalyzed cross-coupling to directly construct versatile α-aryl-esters by utilizing readily available aryl bromides (or chlorides) and malonates. These gram-scale approaches occur with turnovers of up to 1560 and are smoothly conducted by the usage of a low catalyst loading, a new available ligand, and a green solvent. A variety of functional groups
Cationic Ir/Me-BIPAM-Catalyzed Asymmetric Intramolecular Direct Hydroarylation of α-Ketoamides
作者:Tomohiko Shirai、Hajime Ito、Yasunori Yamamoto
DOI:10.1002/anie.201400147
日期:2014.3.3
Asymmetricintramoleculardirecthydroarylation of α‐ketoamides gives various types of optically active 3‐substituted 3‐hydroxy‐2‐oxindoles in high yields with complete regioselectivity and high enantioselectivities (84–98 % ee). This is realized by the use of the cationic iridium complex [Ir(cod)2](BArF4) and the chiral O‐linked bidentate phosphoramidite (R,R)‐Me‐BIPAM.
α-酮酰胺的不对称分子内直接氢芳基化反应可高产率获得各种类型的旋光3-取代3-羟基2-羟吲哚,具有完全的区域选择性和高对映选择性(84–98%ee)。这是通过使用阳离子铱络合物[Ir(cod)2 ](BAr F 4)和手性O联双齿亚磷酰胺(R,R)-Me-BIPAM来实现的。
Ruthenium Porphyrin Catalyzed Intramolecular Carbenoid C−H Insertion. Stereoselective Synthesis of Cis-Disubstituted Oxygen and Nitrogen Heterocycles
作者:Wai-Hung Cheung、Shi-Long Zheng、Wing-Yiu Yu、Guo-Chuan Zhou、Chi-Ming Che
DOI:10.1021/ol034806q
日期:2003.7.1
[reaction: see text] A ruthenium porphyrin-catalyzed stereoselective intramolecularcarbenoid C[bond]H insertion is described. Using [Ru(II)(TTP)(CO)] as catalyst, aryl tosylhydrazones are converted to 2,3-dihydrobenzofurans, 2,3-dihydroindoles, and beta-lactams in good yields and remarkable cis selectivity (up to 99%). Enantioselective synthesis of 2,3-dihydrobenzofurans is also achieved with [Ru(II)(D(4)-Por*)(CO)]
The preparation of a series of N-hydroxy peptides is described, along with their acylation on the oxygen of the pseudopeptide bond. Nineteen N-acyloxy peptides, first examples of this new class of pseudopeptides, were thus synthesized; they present a range of acyl groups, including N-protected amino acyl groups. Possibilities of elongation for these pseudopeptides were also investigated.
Simple and Mild Method for Preparation of .ALPHA.-Pyridinecarboxylates and .ALPHA.-Pyridyl Ketones via Trimethylstannyl Derivatives.
作者:Yutaka YAMAMOTO、Hidekazu OUCHI、Takuo TANAKA
DOI:10.1248/cpb.43.1028
日期:——
Alkoxycarbonylation and acylation at the α-position of pyridine, quinoline, and isoquinoline via the respective trimethylstannyl derivatives were satisfactorily performed by employing ethyl chloroglyoxylate and acylformyl chloride under mild conditions.