tris(pentafluorophenyl)borane, B(C6F5)3, and BF3·Et2O are shown to catalyze the regioselective hydrothiolation of a wide range of terminal 1-aryl-1,3-dienes. In the case of internal 1,3-dienes, B(C6F5)3 is by far the better catalyst than BF3·Et2O. The process features mild reaction conditions, broad scope, and low catalyst loading, and it can be scaled up quickly over a short reaction time. The reactions are rate-limited
报道了用于合成仲和叔烯丙基硫醚的无过渡金属的1,3-二烯氢硫醇化反应。硼路易斯酸三(五氟苯基)硼烷,B(C 6 F 5)3和BF 3 ·Et 2 O已显示出催化范围广泛的末端1-芳基-1,3-二烯的区域选择性氢硫醇化反应。在内部1,3-二烯的情况下,与BF 3 ·Et 2相比,B(C 6 F 5)3是更好的催化剂。O.该工艺的特点是反应条件温和,适用范围广,催化剂用量低,并且可以在较短的反应时间内迅速扩大规模。如高水平DFT计算所示,反应是通过1,3-二烯与硫醇-硼路易斯酸配合物的1-芳基定向质子化,然后将硫化物阴离子转移到所得的烯丙基阳离子上来进行的,从而限制了反应的速率。
An Approach to the Regioselective Diamination of Conjugated Di- and Trienes
作者:Anton Lishchynskyi、Kilian Muñiz
DOI:10.1002/chem.201103435
日期:2012.2.20
It's do or diaminate: The selective diamination of 1,3‐butadienes in the presence of hypervalent iodine reagents has been developed. This oxidation process proceeds with complete selectivity in favor of diamination. Depending on the substrate, it proceeds either with 1,2‐ or 1,4‐regioselectivity (see scheme).
bioinsipred gold‐catalyzed tandem Diels–Alder/Diels–Alderreaction of an enynal and a 1,3‐diene, forming the highly‐strained benzotricyclo[3.2.1.02,7]octane skeleton, was reported. In contrast, a Diels–Alder/Friedel–Crafts tandem reaction occurred instead when silver salts were used as the catalyst. Although both reactions experienced the similar Diels–Alderreaction of a pyrylium intermediate with a
hydroalkylation of dienes with stabilized carbon nucleophiles has been made, hydroalkylation of dienes with unstabilized carbon nucleophiles has remained a challenge. In this article, we report a protocol for nickel-catalyzed hydroalkylation of dienes with hydrazones, which serve as equivalents of alkyl carbon nucleophiles. In addition, we developed a protocol for hydroalkenylation of dienes with α,β-unsaturated
Free radical-mediated alkylation of general alkenes is a challenging and largely unmet goal. Herein, we disclose a conceptually novel "polarity umpolung" strategy for radical alkylation of alkenes using a portfolio of easily-accessed, dual-function alkylating reagents. This is achieved by substituting inherently nucleophilic alkyl radicals with electrophilic sulfone-decorated surrogates, thus inverting