The alkylation of α-ethoxycarbamates is accomplished with organo-lead, -zinc, and -copper reagents in the presence of Lewis acids. The reaction proceeds with high diastereoselectivity in good to high yields.
Tetraalkllleads (R4Pb) reacted quite smoothly with aldehydes R′CHO in the presence of TiCl4 to produce the corresponding alcohols (RCHOHR′) in high to good yields. The reagent system, R4Pb/TiCl4, exhibited high chemoselectivity; only aldehydes underwent the alkylation in the presence of ketones. Further, the newreagent exhibited high 1,2- and 1,3-asymmetric induction. The transfer order of alkyl groups
and DFT-calculated IR spectra of n-Bu4M (M = Si, Ge, Sn, Pb), (CH3CH2CH213CD2)4Sn, and n-BuAuPPh3-d15 are reported and assigned. The asymmetric CHstretchingvibration of the CH2 group adjacent to the metal atom appears as a distinct shoulder at ∼2934 cm–1, whereas for other CH2 groups it is located at ∼2922 cm–1. The characteristic peak at ∼2899 cm–1 is attributed to an overtone of a symmetric CH2 bend
报告了n -Bu 4 M(M = Si,Ge,Sn,Pb),(CH 3 CH 2 CH 2 13 CD 2)4 Sn和n -BuAuPPh 3 - d 15的观察值和DFT计算的IR谱,并且已分配。与金属原子相邻的CH 2基团的不对称CH拉伸振动在〜2934 cm –1处表现为明显的肩峰,而对于其他CH 2基团,其位于〜2922 cm –1处。在〜2899 cm –1处的特征峰归因于对称CH 2的泛音在〜1445 cm –1处弯曲。在n -BuAuPPh 3 - d 15中,丁基的CH拉伸振动向较低的频率偏移约10 cm –1,并提供了两种可能的合理化方法。