Allenylzinc reagents: new trends and synthetic applications

Indium‐Promoted Diastereo‐ and Regioselective Propargylation of Chiral Sulfinylimines

“…This conclusion shows that both methodologies (indium‐ or zinc‐promoted propargylation) are complementary. In the case of the reaction with zinc, transition state V has been proposed in which the zinc atom coordinates to only the nitrogen atom of the imine to form a six‐membered ring in which the imine adopts the most stable s ‐ cis conformation 8a. In our case, we propose transition state VI , also involving a six‐membered ring, but with the simultaneous coordination of the indium atom to both the nitrogen and oxygen atoms of the imine, so fixing a conformation in which nucleophilic attack takes place at the less hindered Si face for imines with the R S configuration (Figure 1).…”

Application of tert-Butylsulfinamide in Total Synthesis of Natural Products

“…他们从溴化物 161 出发, 经过 5 步转化得到叔丁基 亚磺酰亚胺 162, 与原位生成的联烯锌试剂 [49] [50] 2009 年, 林国强课题组 [56] 2019 年, Andrade 课题组 [64] 应用组内发展的叔丁基 亚磺酰亚胺与不饱和酯发生串联 Michael/Mannich 环化 反应 [62] , 引入了三个连续的手性中心, 该立体中心诱导 了后续螺环化反应生成新的立体中心, 进而完成了 (＋)-epi-condyfoline 的首次全合成.…”

tert-Butanesulfinimines: structure, synthesis and synthetic applications

“…Under the optimized conditions, tBS-imines 8 are reacted with excess 88 in the presence of catalytic TMEDA giving anti-adducts 89 as major isomers (420 : 1 : 0 : 0 dr) in good yields (41-87%) (Scheme 44). 90,91 The stereoselectivity of the reaction has been assumed to be the consequence of the high dynamic kinetic resolution of the racemic organozinc reagent 88 through the mono-cooordinated model M15 in which the imine adopts the less energetic conformation C3 (see Fig. 1 in section 2), and in which the zinc atom is coordinated only by the nitrogen of the sulfinyl group.…”