Novel Asymmetric C−C Bond Formation Process Promoted by Et2AlCl and Its Application to the Stereoselective Synthesis of Unusual β-Branched Baylis−Hillman Adducts
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。
Asymmetric Synthesis of β-Amino Carbonyl Compounds with <i>N</i>-Sulfinyl β-Amino Weinreb Amides
作者:Franklin A. Davis、M. Brad Nolt、Yongzhong Wu、Kavirayani R. Prasad、Danyang Li、Bin Yang、Kerisha Bowen、Seung H. Lee、John H. Eardley
DOI:10.1021/jo0402780
日期:2005.3.1
readily add to enantiopure N-sulfinyl β-aminoWeinrebamides providing the corresponding, stable, N-sulfinyl β-amino carbonyl compounds in good to excellent yields. This new methodology represents a general solution to the problem of β-amino carbonyl syntheses, which are important chiral building blocks and constituents of natural products. N-Sulfinyl β-aminoWeinrebamides are prepared by reaction of the
Stereoselective Synthesis of β-Substituted β-Amino Sulfones and Sulfonamides via Addition of Sulfonyl Anions to Chiral <i>N</i>-Sulfinyl Imines
作者:Francisco Velázquez、Ashok Arasappan、Kevin Chen、Mousumi Sannigrahi、Srikanth Venkatraman、Andrew T. McPhail、Tze-Ming Chan、Neng-Yang Shih、F. George Njoroge
DOI:10.1021/ol053132b
日期:2006.2.1
[reaction: see text] A highly stereoselective synthesis of beta-amino sulfones and sulfonamides via addition of sulfonyl anions to chiral N-sulfinyl imines is described. The addition reaction proceeds in good yield (75-99%) and stereoselectivity.
Approaches toward the total syntheses of astins A, B, and C
作者:Jianjun Jiang、Kelly K Schumacher、Madeleine M Joullié、Franklin A Davis、Rajarathnam E Reddy
DOI:10.1016/s0040-4039(00)76775-x
日期:1994.4
Two nonessential amino acids, (+)-(S)-2-aminobutanoic acid and the methyl ester of L-β-phenylalanine [(+)- (R)-3-amino-3-phenyl propanoic acid], were synthesized to provide a tripeptide which will be used in the totalsyntheses of astins A, B, and C.