Asymmetric Intramolecular Hydroamination of Allenes using Mononuclear Gold Catalysts
摘要:
The intramolecular gold-catalyzed asymmetric hydroamination of allenes was studied by screening a series of mononuclear gold(I) and -(III) complexes in combination with silver salts. Among the various chiral monophosphine and diaminocarbene ligands tried, the best catalysts arose from mononuclear gold(I) complexes synthesized from BINOL-based phosphoramidite ligands. The latest were improved by addition of bulky substituents at specific positions of the BINOL scaffold. The resulting gold(I) complexes were combined with selected silver salts to afford efficient catalysts for intramolecular hydroamination of allenes at room temperature or below, with good conversions and enantioselectivities.
A new class of 3,3′-diarylmethyl BINOL derivatives were synthesized and applied to the catalytic asymmetric addition of diethylzinc to aldehydes. These chiral diol auxiliaries could be used as catalysts without the addition of Ti(i-PrO)4 and showed unprecedented catalytic activities and enantioselectivities (up to 94% ee, 5 mol% catalyst loading).
The First Asymmetric Halogen/Metal-Exchange Reaction: Desymmetrization of Alcohols with Enantiotopic Bromoarene Substituents
作者:Daniel Sälinger、Reinhard Brückner
DOI:10.1002/chem.200802488
日期:2009.7.6
Choosy organomagnesium: Prochiral bis(bromoaryl)alcohols were desymmetrized by treatment with iPr2Mg and an enantiopure Li salt. The resulting arylmagnesium intermediate was trapped with electrophiles. Protonolysis and two follow‐up reactions provided the antihistaminic and anticholinergic drug (R)‐orphenadrine (see scheme).
Enantioselective Brønsted Acid Catalyzed Addition Reactions of Methyleneaminopyrrolidine to Imines
作者:Darren J. Dixon、A. Louise Tillman
DOI:10.1055/s-2005-917098
日期:——
A new series of BINOL-derived multidentate Bronsted acid catalysts has been developed for the enantioselective addition of the d 1 -synthon, methyleneaminopyrrolidine. to N-Boc imines, yielding the versatile, protected α-aminohydrazone intermediates in moderate to good ee.
已经开发了一系列新的 BINOL 衍生的多齿布朗斯台德酸催化剂,用于对映选择性加成 d 1 -合成子,亚甲基氨基吡咯烷。到 N-Boc 亚胺,以中等至良好的 ee 产生多功能、受保护的 α-氨基腙中间体。
Enantioselective Fluorescent Recognition of Amino Alcohols by a Chiral Tetrahydroxyl 1,1‘-Binaphthyl Compound
作者:Qin Wang、Xi Chen、Lan Tao、Li Wang、Dan Xiao、Xiao-Qi Yu、Lin Pu
DOI:10.1021/jo061769i
日期:2007.1.1
The tetrahydroxyl derivative of BINOL, (S)- or (R)-1, and its analogues are synthesized. (S)- or (R)-1 can be used to conduct the enantioselectiverecognition of chiral amino alcohols. In comparison with BINOL, the two additional hydroxyl groups of (S)- or (R)-1 have increased the binding of this compound with the amino alcohols and significantly improved the fluorescence quenching efficiency. The
合成了BINOL的四羟基衍生物( S )-或( R ) -1及其类似物。( S )-或( R ) -1可用于进行手性氨基醇的对映选择性识别。与BINOL相比,( S )-或( R ) -1额外的两个羟基增加了该化合物与氨基醇的结合,显着提高了荧光猝灭效率。将( S )-或( R ) -1对氨基醇的荧光响应与其类似物( R )-4和( R ) -6进行比较。结果表明,( S )-或( R ) -1的中心萘基羟基与底物的相互作用是导致观察到的荧光猝灭的原因,并且两个额外的烷基羟基增加了猝灭效率。