Introducing chiral silicon centers was explored for the asymmetric Rh-catalyzed cyclization of dihydrosilanes to enantiomerically enriched spirosilanes as targets to enable access to enantiostable pentacoordinate silicates. The steric rigidity required in such systems demands the presence of two naphthyl or benzo[b]thiophene groups. The synthetic approach to the expanded spirosilanes extends Takai's method (Kuninobu et al. in Angew Chem Int Ed 52(5):1520-1522, 2013) for the synthesis of spirosilabifluorenes in which both a Si-H and a C-H bond of a dihydrosilane are activated by a rhodium catalyst. The expanded dihydrosilanes were obtained from halogenated aromatic precursors. Their asymmetric cyclization to the spirosilanes were conducted with [Rh(cod)Cl]2 in the presence of the chiral bidentate phosphane ligands (R)-BINAP, (R)-MeO-BIPHEP, and (R)-SEGPHOS, including derivatives with P-(3,5-t-Bu-4-MeO)-phenyl (DTBM) groups. The highest enantiomeric excess of 84% was obtained for 11,11'-spirobi[benzo[b]-naphtho[2,1-d]silole] with the DTBM-SEGPHOS ligand.

中文翻译：

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致力于五有机硅酸盐的不对称合成。

探索了引入手性硅中心的方法，以二氢硅烷的不对称Rh催化环化为对映体富集的螺硅烷为目标，从而能够获得对映体的五配位硅酸盐。在这种系统中所需的空间刚性要求存在两个萘基或苯并[b]噻吩基团。扩张的螺硅烷的合成方法扩展了Takai的方法（Kuninobu等人，在Angew Chem Int Ed 52（5）：1520-1522，2013）中合成螺硅二芴的方法，其中Si-H和CH键都与二氢硅烷被铑催化剂活化。膨胀的二氢硅烷从卤化的芳族前体获得。在[Rh（cod）Cl] 2的手性双齿膦配体（R）-BINAP，（R）-MeO-BIPHEP，（R）-SEGPHOS，包括具有P-（3,5-t-Bu-4-MeO）-苯基（DTBM）基团的衍生物。具有DTBM-SEGPHOS配体的11,11'-spirbibi [苯并[b]-萘并[2,1-d]甲硅烷基]的最高对映体过量为84％。