Practical Catalytic Cleavage of C(sp
<sup>3</sup>
)−C(sp
<sup>3</sup>
) Bonds in Amines
作者:Wu Li、Weiping Liu、David K. Leonard、Jabor Rabeah、Kathrin Junge、Angelika Brückner、Matthias Beller
DOI:10.1002/anie.201903019
日期:2019.7.29
The selective cleavage of thermodynamically stable C(sp3)−C(sp3) single bonds is rare compared to their ubiquitous formation. Herein, we describe a general methodology for such transformations using homogeneous copper‐based catalysts in the presence of air. The utility of this novel methodology is demonstrated for Cα−Cβ bond scission in >70 amines with excellent functional group tolerance. This transformation
Triethylammonium acetate (TEAA): a recyclable inexpensive ionic liquid promotes the chemoselective aza- and thia-Michael reactions
作者:Akhilesh K. Verma、Pankaj Attri、Varun Chopra、Rakesh K. Tiwari、Ramesh Chandra
DOI:10.1007/s00706-008-0886-4
日期:2008.9
A new, highlyefficient, inexpensive, recyclable, mild, convenient, and green protocol for chemoselective aza/thia- Michaeladdition reactions of amines/thiols to α,β - unsaturated compounds using triethylammonium acetate ( TEAA ) ionic liquid was developed. The catalyst can be recycled ten times and obviate the need for toxic and expensive catalysts.
The 1,4-conjugate addition of primary, secondary and aromatic amines, thiols, and carbamate to α,β-unsaturated compounds mediated by a catalytic amount (0.5 mol%) of RuCl 3 in poly(ethylene glycol) (PEG) provides the desired β-substituted carbonyls in high yields. In particular, we found that primary aliphatic and aromatic amines produced the single adducts as the sole products in very high yields
Borax as an Efficient Metal-Free Catalyst for Hetero-Michael Reactions in an Aqueous Medium
作者:Sahid Hussain、Saitanya K. Bharadwaj、Mihir K. Chaudhuri、Harjyoti Kalita
DOI:10.1002/ejoc.200600691
日期:2007.1
Borax, a naturally occurring material, very efficiently catalyzed the conjugate addition of thiols, dithiols and amines to α,β-unsaturated ketones, nitriles, amides, aldehydes and esters in an aqueousmedium to afford the corresponding Michael adducts in good yields at room temperature. Recycling of the catalyst and scaling up of the reactions are important attributes of this catalysis. The reactions
Cellulose-Supported Copper(0) Catalyst for Aza-Michael Addition
作者:K. Reddy、Nadakudity Kumar
DOI:10.1055/s-2006-949623
日期:2006.9
Cellulose-supported copper(0) efficiently catalyzes the aza-Michael reaction of N-nucleophiles, such as amines and imidazoles with α,β-unsaturated compounds to produce the corresponding β-amino compounds and N-substituted imidazoles in excellent yields. The reactions are facile and the recovered catalyst is used for several cycles with consistent activity.