A convenientroute to 2-lithio-1,3-butadiene from chloroprene via a 2-stannyl-1,3-butadiene is presented, and the regioselecdve additions to a variety of carbonyl groups are demonstrated.
Game, set, and match: The first regio‐ and enantioselective version of the title reaction is described. The chiral catalyst prepared in situ from CrCl3 and a non‐C2‐symmetric bis(oxazoline) ligand 1 affords the valuable chiral β‐allenols regioselectively in good yields with excellent ee values. R=aryl, alkyl.
Racemic and diastereoselective synthesis of alkyl(1,3-butadien-2-yl)methanols via a novel homoallenylboration of aldehydes with diisopropyl 2,3-butadien-1-ylboronate
作者:Raman Soundararajan、Guisheng Li、Herbert C. Brown
DOI:10.1016/0040-4039(95)00311-y
日期:1995.4
3-butadien-1-ylboronate has been prepared by a simple method and its utility as a novel homoallenylborating reagent has been demonstrated with a series of aldehydes. Also, a high diastereoselectivity of this reagent in its reaction with an α-chiral aldehyde has been established.
Asymmetric Synthesis of (1,3-Butadien-2-yl)methanols from Aldehydes via [1-(Silylmethyl)allenyl]methanols
作者:María Durán-Galván、Brian T. Connell
DOI:10.1002/ejoc.201000199
日期:2010.5
[1-(Silylmethyl)allenyl]methanols 2 were efficiently synthesized fromaldehydes and (4-bromobut-2-ynyl)trimethylsilane in the presence of a catalytic amount of CrCl 2 and tridentate carbazole ligands. The desired compounds were obtained with good yields (43-88%) and enantioselectivities (55-78 % ee). Alcohols 2 may be treated with TBAF or 2 M HCl in the case of aliphatic substrates, to provide (1,