- Iridium-Catalyzed Reductive Strecker Reaction for Late-Stage Amide and Lactam Cyanation
-
A new iridium-catalyzed reductive Strecker reaction for the direct and efficient formation of α-amino nitrile products from a broad range of (hetero)aromatic and aliphatic tertiary amides, and N-alkyl lactams is reported. The protocol exploits the mild and highly chemoselective reduction of the amide and lactam functionalities using IrCl(CO)[P(C6H5)3]2 (Vaska's complex) in the presence of tetramethyldisiloxane, as a reductant, to directly generate hemiaminal species able to undergo substitution by cyanide upon treatment with TMSCN (TMS=trimethylsilyl). The protocol is simple to perform, broad in scope, efficient (up to 99 % yield), and has been successfully applied to the late-stage functionalization of amide- and lactam-containing drugs, and naturally occurring alkaloids, as well as for the selective cyanation of the carbonyl carbon atom linked to the N atom of proline residues within di- and tripeptides.
- Fuentes de Arriba, ángel L.,Lenci, Elena,Sonawane, Mahendra,Formery, Odilon,Dixon, Darren J.
-
supporting information
p. 3655 - 3659
(2017/03/21)
-
- A practical in situ generation of the schwartz reagent. reduction of tertiary amides to aldehydes and hydrozirconation
-
A new, highly efficient in situ protocol (Cp2ZrCl2/LiAlH(OBu-t)3) is described for the generation of the Schwartz reagent which provides a convenient method for the amide to aldehyde reduction and the regioselective hydrozirconation-iodination of alkynes and alkenes. Highlighted are chemoselective reductions of benzamides derived by directed ortho metalation (DoM) chemistry, allowing the synthesis of valuable 1,2,3-substituted benzaldehydes. The single-step, three-component process proceeds in a very short reaction time, shows excellent functional group compatibility, and uses inexpensive and long-storage stable reducing reagents.
- Zhao, Yigang,Snieckus, Victor
-
p. 390 - 393
(2014/04/03)
-
- Nickel-catalyzed cross-coupling of unactivated alkyl halides and tosylate carrying a functional group with alkyl and phenyl Grignard reagents
-
By the use of catalytic amounts of a nickel salt and a 1,3-butadiene, primary and secondary alkyl Grignard reagents undergo cross-coupling with alkyl bromides, iodide, and tosylate carrying a functional group such as amide, ester, and ketone at 0 °C in THF. The present procedure provides a simple, convenient, and practical method for construction of carbon chains in the presence of various functional groups. PhMgBr also gave the corresponding coupling product in a moderate yield.
- Singh, Surya Prakash,Terao, Jun,Kambe, Nobuaki
-
experimental part
p. 5644 - 5646
(2011/02/25)
-