Development of Enantioselective Palladium‐Catalyzed Alkene Carboalkoxylation Reactions for the Synthesis of Tetrahydrofurans

The Pd‐catalyzed coupling of γ‐hydroxyalkenes with aryl bromides affords enantiomerically enriched 2‐(arylmethyl)tetrahydrofuran derivatives in good yield and up to 96:4 e.r. This transformation was achieved through the development of a new TADDOL/2‐arylcyclohexanol‐derived chiral phosphite ligand. The transformations are effective with an array of different aryl bromides, and can be used for the preparation of products bearing quaternary stereocenters.The construction of enantiomerically enriched tetrahydrofurans is accomplished by asymmetric Pd‐catalyzed cross‐coupling reactions between γ‐hydroxyalkenes and aryl bromides. Use of a palladium catalyst supported by a new TADDOL‐derived chiral phosphite ligand provides the tetrahydrofuran products in good yield with up to 96:4 e.r. (see scheme).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115961/1/anie_201506884_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115961/2/13390_ftp.pd

Asymmetric Palladium‐Catalyzed Alkene Carboamination Reactions for the Synthesis of Cyclic Sulfamides

The synthesis of cyclic sulfamides by enantioselective Pd‐catalyzed alkene carboamination reactions between N‐allylsulfamides and aryl or alkenyl bromides is described. High levels of asymmetric induction (up to 95:5 e.r.) are achieved using a catalyst composed of [Pd2(dba)3] and (S)‐Siphos‐PE. Deuterium‐labelling studies indicate the reactions proceed through syn‐aminopalladation of the alkene and suggest that the control of syn‐ versus anti‐aminopalladation pathways is important for asymmetric induction.Aminate the double bond! The enantioselective Pd‐catalyzed coupling of aryl or alkenyl bromides with N‐allylsulfamides affords substituted cyclic sulfamides in good yield with high levels of asymmetric induction (see scheme). The reactions proceed through stereoselective syn‐aminopalladation of the alkene, which is important for high enantioselectivity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134229/1/chem201600887-sup-0001-misc_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134229/2/chem201600887.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134229/3/chem201600887_am.pd

Harnessing the β‑Silicon Effect for Regioselective and Stereoselective Rhodium(II)-Catalyzed C–H Functionalization by Donor/Acceptor Carbenes Derived from 1‑Sulfonyl-1,2,3-triazoles

The regioselective and enantioselective intermolecular sp³ C–H functionalization of silicon-substituted alkanes was accomplished using Rh₂(<i>S-</i>NTTL)₄ with readily available 1-sulfonyl-1,2,3-triazoles as carbene precursors. These reactions generate a diverse array of stereodefined substituted silaalkanes

Synthesis of Cyclic Guanidines via Silver-Catalyzed Intramolecular Alkene Hydroamination Reactions of <i>N</i>‑Allylguanidines

The silver-catalyzed hydroamination of tosyl-protected <i>N</i>-allylguanidines is described. These reactions provide substituted cyclic guanidines in high yields. The reactions are amenable to the construction of quaternary stereocenters as well as both monocyclic and bicyclic guanidine products