A Novel Approach for the Formation of Carbon−Nitrogen Bonds: Azidation of Alkyl Radicals with Sulfonyl Azides
作者:Cyril Ollivier、Philippe Renaud
DOI:10.1021/ja004129k
日期:2001.5.1
Two preparatively attractive methods for the azidation of alkyl radicals are described. Secondary and tertiary alkyl iodides and dithiocarbonates are easily converted into the corresponding azides, either by reaction with ethanesulfonyl azide in the presence of dilauroyl peroxide, or by treatment with benzenesulfonyl azide and hexabutylditin in the presence of a radical initiator. Interestingly, intramolecular
Synthesis of the 2H-quinolizin-2-one scaffold via a stepwise acylation—intramolecular annulation strategy
作者:Swaminathan R. Natarajan、Meng-Hsin Chen、Stephen T. Heller、Robert M. Tynebor、Ellen M. Crawford、Cui Minxiang、Han Kaizheng、Jingchao Dong、Bin Hu、Wu Hao、Shu-Hui Chen
DOI:10.1016/j.tetlet.2006.05.089
日期:2006.7
A rapid entry into the 2H-quinolizin-2-one starting from 2-alkyl pyridine has been developed. Initial deprotonation of a 2-alkyl pyridine followed by acylation with a β-TMS-propyonate derivative provides acyclic precursors that after deprotection undergoes a 6-endo-trig cyclization to yield the desired 2H-quinolizin-2-one derivative. This synthetic strategy was found to be generally applicable as evidenced
An Ireland−Claisen Approach to β-Alkoxy α-Amino Acids
作者:James P. Tellam、Gabriele Kociok-Köhn、David R. Carbery
DOI:10.1021/ol802169j
日期:2008.11.20
A diastereoselective Ireland-Claisen approach to beta-alkoxy alpha-amino acid esters is reported. Amino acid esters of enol ethereal allylic alcohols undergo facile syn-selective [3,3]-sigmatropic rearrangement via silyl keteneacetals. Substrate synthesis, rearrangement development, stereoselectivity, and product elaboration are discussed.
Remote Stereocontrol in [3,3]-Sigmatropic Rearrangements: Application to the Total Synthesis of the Immunosuppressant Mycestericin G
作者:Nathan W. G. Fairhurst、Mary F. Mahon、Rachel H. Munday、David R. Carbery
DOI:10.1021/ol203300k
日期:2012.2.3
3]-sigmatropic rearrangement has been used to access biologically important β,β′-dihydroxy α-amino acids. The rearrangement reported is highly stereoselective and offers excellent levels of remotestereocontrol. This strategy has been used to synthesize the natural immunosuppressant mycestericin G and ent-mycestericin G, allowing for a revision of absolute configuration of this natural product.
A systematic investigation of radical haloacetal cyclizations (Ueno-Stork reaction) where the acetal center is the unique stereogenic element is reported. This highly diastereoselective reaction can be used for the preparation of polysubstituted tetrahydrofurans and gamma-lactones. We report herein the full experimental details of reactions where up to three new chiral centers are created. To demonstrate