Synthesis of homopropargyl alcohols via insertion of allenyl carbenoids into acyclic organozirconium bonds
作者:Jozef Stec、Alan R. Henderson、Richard J. Whitby
DOI:10.1016/j.tetlet.2011.12.081
日期:2012.2
Insertion of allenyl carbenoids (3-tosyloxy-1-lithioalk-1-ynes) into organozirconium complexes gave allenyl-zirconocenes via a 1,2-zirconate rearrangement. Trapping of the allenyl-zirconium species with aldehydes and ketones gave, after hydrolysis, a series of homopropargyl alcohols. Enantioenriched products were prepared by insertion of the lithium carbenoid derived from (S)-but-3-yn-2-yl 4-toluenesulfonate
Chiral Brønsted Acid Catalyzed Enantioselective Synthesis of <i>anti</i>-Homopropargyl Alcohols via Kinetic Resolution–Aldehyde Allenylboration Using Racemic Allenylboronates
作者:Andy S. Tsai、Ming Chen、William R. Roush
DOI:10.1021/ol4003459
日期:2013.4.5
A chiral phosphoric acidcatalyzedkinetic resolution/allenylboration of racemicallenylboronates with aldehydes is described. Allenylboration of aldehydes with 2.8 equiv of allenylboronate (±)-1 in the presence of 10 mol % of catalyst (R)-2 provided anti-homopropargylalcohols 3 in 83–95% yield with 9:1 to 20:1 diastereoselectivity and 73–95% ee. The catalyst enables the kinetic resolution of the