已经开发了一种三组分路易斯酸碱(Lewis trio),它涉及大体积的手性伯胺B(C 6 F 5)3和大体积的叔胺,作为对映选择性脱硫反应的有效烯胺催化剂。发现笨重的叔胺可通过沮丧的相互作用激活笨重的伯叔叔二胺-硼烷路易斯对,从而催化烯胺。所得的手性笨重的Lewis三重奏(BLT)允许以实用且高度立体控制的方式通过与β-酮羰基或α-支链醛直接脱硫来构建手性二硫化物。
commercially available aldehyde and chiral tert-butanesulfinamide, a series of chiral sulfinamide phosphines (Xiao-Phos) were synthesized via a two-step condensation-nucleophilic addition procedure. In most cases, nucleophilic addition of the N-tert-butanesulfinyl imine with diphenyl methyl phosphonic lithium showed high diastereoselectivity (d.r>20:1) with BF3 as additives. Following removal of the chiral
Enantio‐ and Diastereoswitchable C−H Arylation of Methylene Groups in Cycloalkanes
作者:Michal S. Andrä、Lukas Schifferer、Corina H. Pollok、Christian Merten、Lukas J. Gooßen、Jin‐Quan Yu
DOI:10.1002/chem.201902046
日期:2019.6.26
A complementary set of chiral N,N‐ligands enables the Pd‐catalyzed β‐C−H arylation of unbiased internal methylene groups in good yield and with high levels of enantio‐ and diastereoinduction. Both the dia‐ and enantioselectivity can be reversed, thus allowing the selective arylation of any of the four β‐C−H bonds in cycloalkanecarboxamides of various ring sizes. The method is applicable to a broad
Asymmetric synthesis of stable α-aminoboronic esters catalyzed by N-heterocylic carbene and copper(i) chloride
作者:Jinbo Chen、Ling-yan Chen、Yue Zheng、Zhihua Sun
DOI:10.1039/c4ra02229g
日期:——
Bis(pinanediolato)diboron (B2pnd2) was used as the nucleophile instead of bis(pinacolato)diboron in the stereospecific synthesis of α-aminoboronic esters catalysed by a triazole-based N-hetereocyclic carbene (NHC) and Cu(I) chloride. The resulting pinanediol-protected α-aminoboronic esters have significantly improved stability over the pinacol derivatives.
Design, Synthesis, and Application of a Chiral Sulfinamide Phosphine Catalyst for the Enantioselective Intramolecular Rauhut-Currier Reaction
作者:Xiao Su、Wei Zhou、Yangyan Li、Junliang Zhang
DOI:10.1002/anie.201500907
日期:2015.6.1
A novel class of chiral sulfinamide phosphine catalysts (Xiao‐Phos) are reported, which can be easily prepared from inexpensive commercially available starting materials. The Xiao‐Phos catalysts showed good performance in enantioselectiveintramolecular Rauhut–Currier reactions, generating α‐methylene‐γ‐butyrolactones in high yields with up to 99 % ee under mild conditions. Moreover, kinetic resolution