Iron-Catalyzed Regio- and Stereoselective Hydrosilylation of 1,3-Enynes To Access 1,3-Dienylsilanes

Abstract

A regio- and stereoselective hydrosilylation of 1,3-enynes with primary and secondary silanes to access 1,3-dienylsilanes is accomplished by employing an iron precatalyst bearing iminopyridine-oxazoline (IPO) ligand. The hydrosilylation proceeds via syn-addition of a Si–H bond to the alkyne group of 1,3-enynes, incorporating the silyl group at the site proximal to the alkene. The reaction features mild conditions, broad substrate scope, and good functional group tolerance. The synthetic utility was demonstrated by gram-scale reactions and further transformations.

Cobalt-Catalyzed Sequential Site- and Stereoselective Hydrosilylation of 1,3- and 1,4-Enynes

“…Reactions with 1,3-enynes might proceed in more possible pathways as well. A few protocols on metal-catalyzed hydrosilylation of 1,3-enynes have been reported (Scheme b). , However, only one Si–H bond reacted even if the silanes contain multiple Si–H bonds. The reaction modes are normally selective 1,2- and 1,4-addition.…”

Regio- and Enantioselective CuH-Catalyzed 1,2- and 1,4-Hydrosilylation of 1,3-Enynes

“…[27][28][29] However, hydrosilylation reaction of 1,3-enynes remains underdeveloped, in contrast to the signi cant advances in the hydrosilylation of alkenes, [30][31][32][33][34] alkynes [35][36][37][38][39][40] and 1,3-dienes. [41][42][43][44][45][46][47][48][49][50] Such reactions can proceed through three main pathways, including 1,2-/3,4-, [51][52][53][54][55][56][57] and 1,4-hydrosilylations, [58][59][60][61][62] which makes control of regio-, stereo-, and enantioselectivity di cult (Fig. 1a).…”

Iron-Catalyzed Cross-Coupling of α-Allenyl Esters with Grignard Reagents for the Synthesis of 1,3-Dienes

“… 6 The control of regio- and stereoselectivity still constitutes the main challenge in these transition metal-catalyzed 1,3-diene synthesis reactions. While palladium catalysts play a major role in these reactions, methods based on inexpensive 3d metal catalysts, such as iron, 7 copper, 8 and nickel, 9 are still underdeveloped. Iron catalysis has received considerable attention in organic chemistry due to its high earth abundance and low toxicity.…”