Imam Sadiq (a.s) (83-148 H) had a large number of students which is narrated to be more than 4000 students. Among his students we can find a number of great Sunni individuals and jurisprudents such as Abu Hanifa al-Nu'man ibn Sabet (80-150 H) and Malik ibn Anas (93-179 H).
Abu Hanifa was one of the students of Imam Sadiq benefiting from Imam Sadiq for two years. It is narrated from Abu Hanifa, for instance, saying
"If there was not the two years (being student of Imam Sadiq) surely Nu'man (Abu Hanifa) would be perished."
Moreover, Abu Hanifa in another place says as narrated that
"if there was not Mohammed ibn Ja'far people would not know their rituals of Hajj (Manasik Hajj)
It is narrated from Malik ibn Anas saying
"I Swear to Allah my eyes has not seen anyone better than Mohammed ibn Ja'far regarding Asceticism, bounty, worship and piety…"
It is worth to mention that other two great Sunni jurisprudents are Mohammed ibn Idris al-Shafe'i (150-204 H) who was the teacher of the other well-known Sunni jurist named Ahmad ibn Hanbal (168-241) while al-Shafe'i was one of the students of Malik ibn Anas whose teacher was Imam Sadiq (a.s). Hence, the leaders of Sunni jurists directly or indirectly are students of Imam Sadiq (a.s).
 Al-Savaeq al-Muhraqa, ibn Hajar Meisami. P 120./ The history of Islamic denominations, Mohammed Abu Zohre, chapter Abu Hanifa, P 72
 Sharhu al-Akhbar, fi Fazael al-Aematal Athar. V3, P 299
 The history of Islamic denominations, Mohammed Abu Zohre, chapter Abu Hanifa P31 لولا السنتان لهلک النعمان
 Man La Yahzorohol Faqih, ibn Babivayh, Mohammed ibn Ali, , V2, P519 وَ رُوِيَ عَنْ أَبِي حَنِيفَةَ النُّعْمَانِ بْنِ ثَابِتٍ أَنَّهُ قَالَ: لَوْ لَا جَعْفَرُ بْنُ مُحَمَّدٍ مَا عَلِمَ النَّاسُ مَنَاسِكَ حَجِّهِمْ
 Al-Amali, ibn Babivayh, Mohammed ibn Ali, P 542 حَدَّثَنَا عَلِيُّ بْنُ أَحْمَدَ بْنِ مُوسَى رِضْوَانُ اللَّهِ عَلَيْهِ قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ أَبِي عَبْدِ اللَّهِ الْكُوفِيُّ قَالَ حَدَّثَنَا مُوسَى بْنُ عِمْرَانَ الْحَنَفِيُّ عَنْ عَمِّهِ الْحُسَيْنِ بْنِ يَزِيدَ النَّوْفَلِيِّ قَالَ سَمِعْتُ مَالِكَ بْنَ أَنَسٍ الْفَقِيهَ يَقُولُ وَ اللَّهِ مَا رَأَتْ عَيْنِي أَفْضَلَ مِنْ جَعْفَرِ بْنِ مُحَمَّدٍ ع زُهْداً وَ فَضْلًا وَ عِبَادَةً وَ وَرَعاً