Double O–H insertion reactions of cyclic diazo amides 1 and dihydroxy compounds 2 in the presence of rhodium(II) acetate catalyst have been achieved, which ultimately led to the facile synthesis of prototype bis(3-oxy-1,3-dihydro-2H-indol-2-one) systems. This facile double O–H insertion reaction protocol was successfully applied to synthesize several C2-symmetric macrocycles having oxindole units incorporated
在乙酸铑(II)催化剂存在下,环状重氮酰胺1和二羟基化合物2的双O-H插入反应已实现,最终导致了原型双(3-oxy-1,3-dihydro- 2 H -indol-2-one)系统。这种简便的双OH插入反应方案已成功地用于合成几个具有完全非对映选择性并带有羟吲哚单元的C 2对称大环。
Rearrangement of an Intermediate Cyclopropyl Ketene in a Rh<sup>II</sup>-Catalyzed Formal [4 + 1]-Cycloaddition Employing Vinyl Ketenes as 1,4-Dipoles and Donor–Acceptor Metallocarbenes
作者:Kevin X. Rodriguez、Nicolai Kaltwasser、Tiffany A. Toni、Brandon L. Ashfeld
DOI:10.1021/acs.orglett.7b00618
日期:2017.5.19
formal [4 + 1]-cycloaddition approach toward spirooxindole cyclopentenones is described. The diastereoselective cyclopropanation of vinyl ketenes with diazooxindoles as C1 synthons initiated a relatively mild formal [1,3]-migration of an intermediate cyclopropyl ketene to provide spirooxindoles in good to excellent yields (36–99%).
Reaction of cyclic diazoamides with furan systems using rhodium(II) acetate as a catalyst afforded a variety of (3Z)-3-[(2E)-4-oxopent-2-en-1-ylidene]indol-2-ones in a regio- and diastereo-selective manner. The diastereoselectivity was based on the flow rate of cyclic diazoamides. The representative products were characterized by single-crystal X-ray analyses.
‘On-water’ generation of carbonyl ylides from diazoamides: rhodium(II) catalyzed synthesis of spiroindolo-oxiranes and -dioxolanes with an interesting diastereoselectivity
作者:Sengodagounder Muthusamy、Rajagopal Ramkumar
DOI:10.1016/j.tet.2015.06.076
日期:2015.9
The ‘on-water’ generation of carbonylylide dipoles from diazoamides in the presence of rhodium(II) acetate dimer as the catalyst was demonstrated for the first time to synthesize spiroindolo-oxiranes and -dioxolanes. Unusual generation of carbonylylides with aromatic aldehydes having electron-withdrawing substituents and 1,3-dipolar cycloaddition reactions with aromatic aldehydes having electron-donating
spirodihydrofurooxindoles through the multicomponent reactions of cyclic diazoamides was successfully achieved for the first time. The stereochemistry of the spirofurooxindole is unequivocally corroborated by the single-crystal X-ray analysis of the representative product 4o. Interestingly, these reactions were extended to double multicomponent reactions of bis-cyclic diazoamides to afford the respective