Regio- and Enantioselective Control in the Reactions of α-(<i>N</i>-Carbamoyl)alkylcuprates with Allylic Phosphates
作者:R. Karl Dieter、Vinayak K. Gore、Ningyi Chen
DOI:10.1021/ol0364576
日期:2004.3.1
Alpha-(N-carbamoyl)alkylcuprates (RCuCNLi or R2CuLi) react with allylic phosphates to afford homoallylic amines in good chemical yields. Regioselectivity is governed by steric factors in both the cuprate reagent and phosphate substrate and systems can be designed to give either the S(N)2' or S(N)2 substitution product cleanly. Excellent enantioselectivities can be achieved with either a scalemic a
The present invention relates to aryl olefinic azacyclic compounds and aryl acetylenic azacyclic compounds, including pyridyl olefinic cycloalkylamines and pyridyl acetylenic cycloalkylamines. The present invention also relates to prodrug derivatives of the compounds of the present invention.
Asymmetric Allylboration of Cyclic Imines and Applications to Alkaloid Synthesis
作者:T. Robert Wu、J. Michael Chong
DOI:10.1021/ja0636791
日期:2006.8.1
Treatment of cyclic imines with 3,3'-disubstituted binaphthol modified allylboronates provides the expected allylated products in good yields and with high stereoselectivities (91-99% ee). The products may be readily transformed into various alkaloids.
Reactivity and Enantioselectivity in the Reactions of Scalemic Stereogenic α-(<i>N</i>-Carbamoyl)alkylcuprates
作者:R. Karl Dieter、Gabriel Oba、Kishan R. Chandupatla、Chris M. Topping、Kai Lu、Rhett T. Watson
DOI:10.1021/jo035845i
日期:2004.4.1
ine and THF soluble CuCN·2LiCl react with vinyl iodides, vinyl triflates, β-iodo-α,β-enoates, propargyl mesylates, and allyl bromide to afford the substitution products with excellent enantioselectivity. Excellent enantiomeric ratios are obtained in the conjugateaddition reactions with methyl vinyl ketone while low enantiomeric ratios can be achieved with acrylate esters using HMPA/TMSCl activation
Asymmetric Lithiation Trapping of <i>N</i>-Boc Heterocycles at Temperatures above −78 °C
作者:Giacomo Gelardi、Graeme Barker、Peter O’Brien、David C. Blakemore
DOI:10.1021/ol402395j
日期:2013.11
The asymmetric lithiation trapping of N-Boc heterocycles using s-BuLi/chiral diamines at temperatures up to −20 °C is reported. Depending on the N-Boc heterocycle, lithiation is accomplished using s-BuLi and (−)-sparteine or the (+)-sparteine surrogate in the temperature range −50 to −20 °C for short reaction times (2–20 min). Subsequent electrophilic trapping or transmetalation–Negishi coupling delivered