A convenient, efficient protocol to prepare diverse spiroisoxazolino-diketopiperazines via a parallel solid-supported synthesis was developed. The key steps are (1) a coupling reaction of an amino acid; (2) tosylation with concomitant β-elimination to form an α, β-unsaturated ester; (3) a 1,3-dipolarcycloaddition with an oxime to form isoxazoline rings; and (4) cyclic cleavage to release the product
Stereospecific 1,4‐Metallate Shift Enables Stereoconvergent Synthesis of Ketoximes
作者:Kai Yang、Feng Zhang、Tongchang Fang、Guan Zhang、Qiuling Song
DOI:10.1002/anie.201906057
日期:2019.9.16
Reported herein is a stereospecific 1,4-metallate rearrangement for single-geometry ketoxime synthesis from oxime chlorides and arylboronic acids. This strategy exhibits broad substrate scope with excellent stereoselectivity under mild reaction conditions. In comparison with the conventional approaches, each configuration of unsymmetric diaryl oximes, as well as the thermodynamically less stable Z isomer
An improved synthesis of 1,2-benzisoxazoles: TBAF mediated 1,3-dipolar cycloaddition of nitrile oxides and benzyne
作者:Christian Spiteri、Pallavi Sharma、Fengzhi Zhang、Simon J. F. Macdonald、Steve Keeling、John E. Moses
DOI:10.1039/b922489k
日期:——
An efficient synthesis of a range of 1,2-benzisoxazoles using an improved1,3-dipolarcycloaddition of nitrileoxides and benzyne is described. Key to the procedure is the in situgeneration of the reactive nitrileoxide and benzyne reaction partners mediated by TBAF. Reactions are complete within 30 s, giving the target products in good to excellent yield.
2,2,2-Trifluoroacetaldehyde <i>O</i>-(Aryl)oxime: A Precursor of Trifluoroacetonitrile
作者:Bo Lin、Yunfei Yao、Yangjie Huang、Zhiqiang Weng
DOI:10.1021/acs.orglett.2c00637
日期:2022.3.18
The preparation of 2,2,2-trifluoroacetaldehyde O-(aryl)oxime, a previously inaccessible precursor of trifluoroacetonitrile, via reaction of hydroxylamine and trifluoroacetaldehyde hydrate is reported. This precursor released CF3CN in quantitative yield under mildly basic conditions. The precursor was successfully used in the synthesis of trifluoromethylated oxadiazoles. The facile, cost-effective,
An efficient entry to 1,2-benzisoxazoles via 1,3-dipolar cycloaddition of in situ generated nitrile oxides and benzyne
作者:Christian Spiteri、Christopher Mason、Fengzhi Zhang、Dougal J. Ritson、Pallavi Sharma、Steve Keeling、John E. Moses
DOI:10.1039/b927235f
日期:——
An efficient protocol for the synthesis of a range of 1,2-benzisoxazoles using an improved1,3-dipolarcycloaddition of nitrileoxides and benzyne is described. Key to the procedure is the in situgeneration of the reactive nitrileoxide and benzyne reactants simultaneously.