Darren Poole

Abstract

Coupled by design: The arylation of sterically demanding α-branched secondary amines was enabled through the design of new palladium catalyst systems. These catalysts help suppress the undesired β-hydride elimination pathways and are effective for the cross-coupling of a wide array of hindered amine nucleophiles with aryl and heteroaryl electrophiles.

[Communication]
Nathaniel H. Park, Ekaterina V. Vinogradova, David S. Surry, Stephen L. Buchwald
Angew. Chem. Int. Ed., June 1, 2015, DOI: 10.1002/anie.201502626. Read article.

All on C: A sequential Rh^I-catalyzed alkyl and alkynyl coupling on a carbene successively establishes a C(sp)-C(sp³) and then a C(sp³)-C(sp³) bond on the original carbenic carbon center. The reaction results in the formation of an all-carbon quaternary center in high efficiency. A rhodium–carbene migratory insertion is proposed as the key step in this transformation.

[Communication]
Ying Xia, Sheng Feng, Zhen Liu, Yan Zhang, Jianbo Wang
Angew. Chem. Int. Ed., May 15, 2015, DOI: 10.1002/anie.201503140. Read article.

A BB method: 1H-imidazol-4(5H)-ones serve as effective and easily available α-amino acid surrogates for the catalytic and highly diastereo- and enantioselective direct construction of N-substituted quaternary α-amino acid derivatives. The reaction is catalyzed by a Brønsted base (BB) and proceeds with different Michael acceptors. EWG=electron-withdrawing group.

[Communication]
Julen Etxabe, Joseba Izquierdo, Aitor Landa, Mikel Oiarbide, Claudio Palomo
Angew. Chem. Int. Ed., April 23, 2015, DOI: 10.1002/anie.201501275. Read article.

Triple whammy: The B(C₆F₅)₃-catalyzed silylative reduction of conjugated nitriles has been developed to afford synthetically valuable β-silyl amines. Based on the mechanistic understanding, a preparative route to enamines was also established using bulky silanes. The reaction is chemoselective, has a broad scope, and proceeds under mild reaction conditions. The mechanism of the triple hydrosilylation is discussed.

[Communication]
Narasimhulu Gandhamsetty, Juhyeon Park, Jinseong Jeong, Sung-Woo Park, Sehoon Park, Sukbok Chang
Angew. Chem. Int. Ed., April 23, 2015, DOI: 10.1002/anie.201502366. Read article.