Catalytic asymmetric synthesis of protected α-hydroxy aldehydes and related 1,2-difunctional chiral building blocks. An enantioselective synthesis of (−)-exo- and (−)-endo-brevicomin
摘要:
Chiral allylic alcohols which were prepared by the addition of functionalized dialkylzincs to alpha,beta-unsaturated aldehydes in good to excellent enantioselectivity, were converted to protected alpha-hydroxy aldehydes and 1,2-amino alcohols without loss of enantiomeric purity. Syn- or anti-1,2-diols can be obtained stereoselectively by a second asymmetric addition to alpha-silyloxy aldehydes. Functionalized 1,2-diols prepared in this way were converted to enantiomerically pure (-)-exo- and (-)-endo-brevicomin (>99% ee). (C) 1997 Elsevier Science Ltd.
Absolute Stereochemistry of Allylic Alcohols, Amines, and Other Ene Moieties: A Microscale Cross Metathesis/Exciton Chirality Protocol
作者:Katsunori Tanaka、Koji Nakanishi、Nina Berova
DOI:10.1021/ja036847n
日期:2003.9.1
microscale chemical/chiroptical protocol for the determination of absoluteconfigurations of allylicalcohols, amines, and related systems has been developed. The method is based on the conversion of the double bonds into a styrene, lambdamax 248 nm (epsilon 15 000), or other styrenoid chromophores by cross olefin metathesis. The obtained styrenoid chromophore then couples with the allylic acylate to yield
已开发出用于测定烯丙醇、胺和相关系统绝对构型的微型化学/手性实验方案。该方法基于通过交叉烯烃复分解将双键转化为苯乙烯、λmax 248 nm (epsilon 15 000) 或其他苯乙烯类生色团。获得的类苯乙烯发色团然后与烯丙基酰化物偶联以产生独特的偶联物。所提出的方法允许确定双键侧翼的两个部分的绝对构型。它还克服了传统苯甲酸烯丙酯方法的限制,该方法会产生弱 CD 对联,在许多情况下,该对联只能观察到一个翼。
Fluorescence Detected Exciton Coupled Circular Dichroism: Development of New Fluorescent Reporter Groups for Structural Studies
In collaboration with Jasco Corporation we have recently developed an FDCD (fluorescencedetectedcircular dichroic) instrument J-465, which eliminates the photoselection artifacts and efficiently collects the emitted light from the sample solution based on the ideal ellipsoidal mirror principle. Using the J-465 we have investigated a variety of fluorophores with/without polarization for exciton-coupled
Cobalt-Catalyzed Enantiospecific Dynamic Kinetic Cross-Electrophile Vinylation of Allylic Alcohols with Vinyl Triflates
作者:Wei-Yuan Ma、Guan-Yu Han、Shaolin Kang、Xiaobo Pang、Xue-Yuan Liu、Xing-Zhong Shu
DOI:10.1021/jacs.1c08695
日期:2021.10.6
unknown. Herein, we report a cobalt-catalyzed enantiospecific vinylation reaction of allylicalcohol with vinyl triflates. This work establishes a new method for the synthesis of enantioenriched 1,4-dienes. The reaction proceeds through a dynamic kinetic coupling approach, which not only allows for direct functionalization of allylicalcohols but also is essential to achieve high chemoselectivity. The
Highly Enantioselective Addition of Mixed Diorganozincs to Aldehydes<sup>†</sup>
作者:Christian Lutz、Paul Knochel
DOI:10.1021/jo971488y
日期:1997.10.1
Synthesis of optically active .beta.,.gamma.-epoxy alcohols and secondary allylic alcohols via diastereoselective addition of .alpha.-(trimethylsilyl)-.alpha.,.beta.-epoxy aldehydes with organometallic compounds