Asymmetric synthesis of chiral sulfoxides and sulfinimines by using N-sulfinylsultam
摘要:
Bornane-10,2-sultam 1 is stereoselectively converted by DMAP-assisted sulfinylation to diastereomerically pure (2R)-N-[(R)-p-tolylsulfinyl]-bornane-10,2-sultam 2 in 77% yield. The crystalline sulfinylating agent 2 reacts with a variety of nucleophiles to afford sulfoxides 3 and sulfinimines 5 in excellent yields and enantioselectivities. (C) 1997 Elsevier Science Ltd.
Two oxathiozolidine‐S‐oxide templates have been developed and used in a four‐component coupling protocol for the synthesis of a wide range of chiralsulfinimines in high enantiomeric excesses. The templates can be synthesized from cheap commodity chemicals in three steps in high yields. Furthermore the template is easily recovered in high yields for recycling.
addition to enantiomerically enriched (tert-butyl)- and (para-tolyl)sulfinimines. This new in situ protocol produces two new CC bonds. Chiral allylic sulfinamides are obtained in high diastereoselectivity and in good yield. Cleavage of the chiral auxiliary leads to synthetically useful allylic amine building blocks, and facile oxidative degradation of the alkene moiety can be used as an approach toward
在催化性 Cp2ZrCl2 和 H2O 存在下,炔烃的碳铝化得到乙烯基丙烷中间体,其在随后添加到对映体富集的(叔丁基)和(对甲苯基)亚磺酰亚胺中充当亲核试剂。这种新的原位协议产生了两个新的 CC 债券。以高非对映选择性和良好收率获得手性烯丙基亚磺酰胺。手性助剂的裂解导致合成有用的烯丙胺结构单元,烯烃部分的易氧化降解可用作获得氨基酸衍生物和分配绝对构型的方法。
Highly Diastereoselective Addition of the Lithium Enolate of α-Diazoacetoacetate to <i>N</i>-Sulfinyl Imines: Enantioselective Synthesis of 2-Oxo and 3-Oxo Pyrrolidines
作者:Changqing Dong、Fanyang Mo、Jianbo Wang
DOI:10.1021/jo702275a
日期:2008.3.1
The highly enantioselective synthesis of 2-oxo and 3-oxo pyrrolidines has been achieved by diastereoselective addition of the lithiumenolate of α-diazoacetoacetate to chiral N-sulfinyl imines, followed by photoinduced Wolff rearrangement or Rh(II)-catalyzed intramolecular N−H insertion.
Lithium enolates derived from ketones may be added to N-sulfinyl imines with high diastereoselectivity. Diastereoselective reduction gave either the syn- or anti-1,3-amino alcohol derivative.
Lewis base-catalyzed diastereoselective Strecker-type reaction between trimethylsilyl cyanide and chiral sulfinimines derived from commercially available (S)-(+)-p-toluenesulfinamide and aliphatic aldehydes proceeded smoothly by using a catalytic amount of tetra-n-butylammonium acetate in DMF to afford the corresponding α-amino nitriles with (Ss,R)-configurations in good to high yields and diastereoselectivities.