Highly stereoselective kinetic resolution of α-allenic alcohols: an enzymatic approach
作者:Wenhua Li、Zuming Lin、Long Chen、Xuechao Tian、Yan Wang、Sha-Hua Huang、Ran Hong
DOI:10.1016/j.tetlet.2015.12.098
日期:2016.2
A highly efficient lipase AK-catalyzed direct kinetic resolution of a variety of α-allenic alcohols was developed. With the complementary to previous studies, the current reaction system is effective on a broad range of substituents (R1) at C(1), such as alkyl, aryl, alkenyl, and alkynyl groups. The Jones–Burgess empirical model was modified to interpret the reversed selectivity during the acetylation
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.