Regio- and stereoselectivity in the concatenated enyne cross metathesis–metallotropic [1,3]-shift of terminal 1,3-diyne

Regioselective Asymmetric Alkynylation of N–Alkyl Pyridiniums

“…Et3N) afforded the pure product 40 (106 mg, 52% yield). Dihydropyridine 42 was synthesized according to general procedure D using allyl bromide (125 µL, 1.45 mmol), imine 17 (100 mg, 0.362 mmol), TBAI (13.4 mg, 0.036 mmol), THF (1 mL), and octa-1,3-diyn-1-ylmagnesium bromide (0.398 mmol, prepared using iPrMgCl•LiCl (511 µL, 0.434 mmol, 0.85 M, 1.2 equiv) was added dropwise to stirred solution of octa-1,3-diyne [6] (42.3 mg, 0.543 mmol, 1 equiv) in anhydrous THF (2 mL) at 0 °C. The mixture was stirred at room temperature for 17h).…”

“…3 In turn, the piperidine heterocycle, a common moiety in bioactive alkaloids and rationally designed drugs 4 has demanded creative new strategies for its construction for many years. [5][6][7][8][9] Moreover, the asymmetric construction of substituted congeners of this important heterocycle has been of the utmost importance in the synthetic pursuit of complex and medicinally relevant molecular targets. 10 Notable biologically active targets that contain multiply-substituted piperidines are depicted in Figure 1A.…”

A Novel Method to Prepare Multisubstituted Pyrazoles

“…卡宾与炔的类似复分解反应具有很高的合成应 用价值 [22] . 文献报道铑和金已经实现了对应卡宾对 炔的分子内插入反应 [21,23,24,31] . 我们设想, 如果能将卡 宾插入与金催化的氧化扩环成酮反应串联起来, 不仅在 机理上比较新颖, 避免了文献中合成相似产物需要用到 的危险的重氮类化合物 [31] , 所得到的结构复杂的多环双…”