Enzyme‐ and Ruthenium‐Catalyzed Enantioselective Transformation of α‐Allenic Alcohols into 2,3‐Dihydrofurans
作者:Bin Yang、Can Zhu、Youai Qiu、Jan‐E. Bäckvall
DOI:10.1002/anie.201601505
日期:2016.4.25
An efficient one‐pot method for the enzyme‐ and ruthenium‐catalyzed enantioselective transformation of α‐allenicalcohols into 2,3‐dihydrofurans has been developed. The method involves an enzymatic kinetic resolution and a subsequent ruthenium‐catalyzed cycloisomerization, which provides 2,3‐dihydrofurans with excellent enantioselectivity (up to >99 % ee). A ruthenium carbene species was proposed as
开发了一种有效的一锅法,用于酶和钌催化的 α-丙二烯醇对映选择性转化为 2,3-二氢呋喃。该方法涉及酶动力学拆分和随后的钌催化环异构化,从而提供具有优异对映选择性的 2,3-二氢呋喃(高达 >99 % ee )。钌卡宾被提议作为环异构化的关键中间体。
Catalytic Enantioselective Allenylation Reactions of Aldehydes with Tethered Bis(8-quinolinolato) (TBOx) Chromium Complex
作者:Guoyao Xia、Hisashi Yamamoto
DOI:10.1021/ja0679578
日期:2007.1.1
The utility of the new class of chiral ligand, tethered bis(8-quinolinol) (TBOxH), is further explored. Its chromiumcomplex, TBOxCr(III)Cl, effectively catalyzes the asymmetric allenylation reactions of various aldehydes at room temperature with high yields (up to 91%) and high enantioselectivities (up to 97% ee). The scope of the present method is shown to be wide, and this method represents an efficient
Chiral Silver Phosphate-Catalyzed Cycloisomeric Kinetic Resolution of α-Allenic Alcohols
作者:Yan Wang、Kuan Zheng、Ran Hong
DOI:10.1021/ja300453u
日期:2012.3.7
A kinetic resolution of a-allenic alcohols is realized through chiral silver phosphate-catalyzed cycloisomerization with high stereoselectivity (selectivity factor up to 189) and tolerance of a variety of functional groups. A mechanistic model is proposed to interpret the origin of the high stereoselectivity and broad substrate scope.
One-Pot Construction of Aza- or Oxa-Bridged Benzocycloheptanes from Readily Available 2,3-Allenyl Malonates or 2,3-Allenols and<i>o</i>-Iodobenzaldehyde or Imine
作者:Qiankun Li、Xinpeng Jiang、Chunling Fu、Shengming Ma
DOI:10.1021/ol102811x
日期:2011.2.4
A Pd(OAc)(2)-catalyzed reaction of 2,3-alkadienyl malonates or 2,3-allenols with o-lodobenzaldehyde or Its N-tosyl imine occurred smoothly In MeCN at 80 degrees C to form the oxa- or aza-bridged benzocycloheptane derivatives with Important biological potential. With the optically active 2,3-allenols, the absolute configurations of all the three chiral centers have been conveniently established.