A General Copper–BINAP-Catalyzed Asymmetric Propargylation of Ketones with Propargyl Boronates
摘要:
An operationally simple copper-BINAP-catalyzed, highly enantioselective propargylation of ketones is presented. The methodology was developed as an enantioselective process for methyl ethyl ketone and shown to be applicable to a wide variety of prochiral ketones. The resulting homopropargyl adducts are versatile latent carbonyls from which gamma-butyrolactones, beta-hydroxy methyl ketones, and beta-hydroxycarboxylates are readily obtained.
Direct Synthesis of <i>B</i>-Allyl and <i>B</i>-Allenyldiisopinocampheylborane Reagents Using Allyl or Propargyl Halides and Indium Metal Under Barbier-Type Conditions
作者:Lacie C. Hirayama、Terra D. Haddad、Allen G. Oliver、Bakthan Singaram
DOI:10.1021/jo300260a
日期:2012.5.4
groups to aldehydes and ketonesusing B-chlorodiisopinocampheylborane (dDIP-Cl) and indium metal. Under Barbier-type conditions, indium metal was used to generate allyl- and allenylindium intermediates, and subsequent reaction with dDIP-Cl successfully promoted the transfer of these groups to boron forming the corresponding chiralboranereagents. The newly formed boranereagents were reacted with aldehydes
<i>B</i>-Allenyl- and <i>B-</i>(γ-Trimethylsilylpropargyl)- 10-phenyl-9-borabicyclo[3.3.2]decanes: Asymmetric Synthesis of Propargyl and α-Allenyl 3°-Carbinols from Ketones
作者:Eliud Hernandez、Carlos H. Burgos、Eyleen Alicea、John A. Soderquist
DOI:10.1021/ol061596j
日期:2006.8.1
Simple and efficient Grignard procedures are reported for the syntheses of B-allenyl-10-(phenyl)-9-borabicyclo[3.3.2]decane (1) and its B-(gamma-trimethylsilylpropargyl) counterpart (2) in both enantiomeric forms. Both add selectively to ketones, providing propargyl- and alpha-silylallenyl 3-degree-carbinols, respectively (i.e., 6 (61-93% ee) and 9 (64-98% ee)). The air-stable boron byproduct is efficiently
Specifically, catalytic enantioselective propargylation was the first example, affording synthetically useful chiral building blocks that have not been easily accessed to date. In addition to the enantioselectivity, the high catalytic activity of the CuOAc-8 complex is noteworthy. Preliminary studies to elucidate the structure-catalyst activity relationship suggested that the high catalytic activity of
Three-Dimensional Correlation of Steric and Electronic Free Energy Relationships Guides Asymmetric Propargylation
作者:Kaid C. Harper、Matthew S. Sigman
DOI:10.1126/science.1206997
日期:2011.9.30
An unexpected synergy between a ligand's
steric bulk and its electronic structure improves a stereoselective catalyst.
一个配体的空间体积和电子结构之间意外产生的协同作用提高了立体选择性催化剂。
Silver-Catalyzed Allenylation and Enantioselective Propargylation Reactions of Ketones
作者:Benjamin L. Kohn、Naoko Ichiishi、Elizabeth R. Jarvo
DOI:10.1002/anie.201206971
日期:2013.4.15
lining: Certain silver complexes are capable of selective catalysis of either allenylation or asymmetric propargylationreactions of ketones. Ligand‐free conditions lead to allenyl alcohols as the major product, whereas ligation with Walphos‐8 gives enantioenriched homopropargyl alcohols. This method can be applied to reactions of prochiral diarylketones to provide optically enriched tertiary diaryl alcohols