A Stereoselective Synthesis of (E)-Allylic Alcohols Via the Hydromagnesiation of Alkynylsilanes

2003 ◽  
Vol 2003 (5) ◽  
pp. 296-298 ◽  
Author(s):  
Mingzhong Cai ◽  
Chunyun Peng ◽  
Hong Zhao ◽  
Wenyan Hao
Keyword(s):  
Stereoselective Synthesis ◽  
Grignard Reagents ◽  
Allylic Alcohols ◽  
High Yields

Hydromagnesiation of alkynylsilanes 1 gives ( Z)-α-silylvinyl Grignard reagents 2, which are reacted with aldehydes or ketones to afford ( Z)-β-silyl allylic alcohols 3 in high yields; intermediates 3 can undergo the desilylation reaction in the presence of anhydrous KF to give ( E)-allylic alcohols 4 in good yields.

A facile stereoselective synthesis of (E)-2,3-disubstituted allylic alcohols via hydromagnesiation of alkylarylacetylenes

2005 ◽  
Vol 2005 (2) ◽  
pp. 121-122 ◽  
Author(s):  
Mingzhong Cai ◽  
Jun Xia
Keyword(s):  
Diethyl Ether ◽  
Stereoselective Synthesis ◽  
Grignard Reagents ◽  
Allylic Alcohols

Hydromagnesiation of alkylarylacetylenes 1 in diethyl ether gave (E)-α-arylvinyl Grignard reagents 2, which reacted with aldehydes or ketones 3 to afford stereoselectively (E)-2,3-disubstituted allylic alcohols 4 in good yields.

Alkynylsilanes as Convenient Precursors for the Stereoselective Synthesis of (E)-Disubstituted Alkenes

2002 ◽  
Vol 2002 (12) ◽  
pp. 608-610 ◽  
Author(s):  
Hong Zhao ◽  
Mingzhong Cai
Keyword(s):  
Stereoselective Synthesis ◽  
Grignard Reagents ◽  
Aryl Iodides ◽  
Alkyl Iodides ◽  
High Yields

Hydromagnesiation of alkynylsilanes 1 gives (Z)-α-silylvinyl Grignard reagents 2, which are reacted with alkyl iodides or aryl iodides in the presence of CuI or Pd(PPh3)4 catalysts to afford (Z)-1,2-disubstituted vinylsilanes 3 in good yields. Intermediates 3 can undergo a desilylation reaction to give (E)-disubstituted alkenes 4 in high yields.

scholarly journals Copper-catalyzed asymmetric allylic substitution reactions with organozinc and Grignard reagents

2008 ◽  
Vol 80 (5) ◽  
pp. 1025-1037 ◽  
Author(s):  
Koen Geurts ◽  
Stephen P. Fletcher ◽  
Anthoni W. van Zijl ◽  
Adriaan J. Minnaard ◽  
Ben L. Feringa
Keyword(s):  
Building Blocks ◽  
Field Work ◽  
Grignard Reagents ◽  
Allylic Alcohols ◽  
Substitution Reactions ◽  
Organometallic Reagents ◽  
Bond Forming ◽  
Allylic Alkylations ◽  
Ferrocenyl Ligands ◽  
High Yields

Asymmetric allylic alkylations (AAAs) are among the most powerful C-C bond-forming reactions. We present a brief overview of copper-catalyzed AAAs with organometallic reagents and discuss our own contributions to this field. Work with zinc reagents and phosphoramidite ligands provided a framework for later developments which employ Grignard reagents and ferrocenyl ligands. High yields and excellent regioselectivities and enantioselectivities are achieved. The AAAs may be more general than previously envisioned, in terms of using substrates functionalized with heteroatoms at various positions; heteroatom substituents at the γ-position provide densely functionalized building blocks. These h-AAA reactions rely on the design of appropriate substrates containing heteroatoms and have allowed us to demonstrate viable new approaches toward the synthesis of versatile organic building blocks. We illustrate that the chiral secondary allylic alcohols, primary homo-allylic alcohols and amines can readily be obtained in high enantiomeric purity in a catalytic asymmetric fashion by copper-catalyzed AAAs. Furthermore, we show that manipulation of the terminal olefin provides chiral building blocks where the ee of the starting materials is preserved.

Diastereoselective Synthesis of Morpholine Derivatives from Grignard Reagents and N-Sulfinyl Imines

Synlett ◽  
2021 ◽  
Author(s):  
Eric P. A. Talbot ◽  
Joseph M. Bateman ◽  
Diana Chan ◽  
Mustafa Moroglu ◽  
Benjamin Rahemtulla
Keyword(s):  
Grignard Reagent ◽  
Stereoselective Synthesis ◽  
Grignard Reagents ◽  
Diastereoselective Synthesis ◽  
Step Process ◽  
Diastereoselective Addition ◽  
Morpholine Derivatives

The stereoselective synthesis of C3-substituted morpholine derivatives has been achieved through a two-step process involving diastereoselective addition of a Grignard reagent to a sulfinyl imine, followed by cyclization.

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